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	All 33 posts	Subject: What can be done to improve the performance of clandestine nitroethane synth?



rev drone (Member) 07-26-99 14:03 No 103078	What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Howdy y'all, For those living in the heart of the nastiest drug-crazed nation on Earth, nitroethane is hard to aquire. This means a person has to eithe do without (sigh), or make their own. After looking at the methods on Rhodium's page, I came to the resoundint conclusion that none of the methods were too great. Now there have been a lot of advacements in Sn2 reactions, especially related to PTC technology. And all these advancements have far outstripped published practical applications. Question: does anyone have any ideas as to how to improve the reaction conditions between diethylsulfate and sodium nitrite? ------------------ -the good reverend drone



rev drone (Member) 07-26-99 14:09 No 103079	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Specificly, can anyone think of a PTC that would be good at efficiently transfering nitrosyl ions into Et2O or some other fairly inert non-polar solvent? ------------------ -the good reverend drone



rev drone (Member) 07-26-99 14:45 No 103080	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	What about using DMF or DMSO as the solvent in conjugation with diethylsulfate and NaNO2? By actually having the components in solution with each other, it would seem yields could be greatly inceased. Diethyl sulfate is cheap, cheap, cheap; it'd sure be nice to get good yields with it too. I'll stop responding to my own post now, ------------------ -the good reverend drone



ymir (Member) 07-26-99 17:59 No 103081	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	A perusal of the original JCS article leads to some observations from the discussion portion, which isn't on Rhodium's page: this method is based on the work of Krause, [D. R. P. 294,755 (1916)] producing the salt, sodium ethyl sulfate which is worked up to yield nitroethane. It's mentioned that dilution leads to more nitrous fumes being produced (leading to ethyl nitrite), lowering the yield of nitroethane. A good shaker is required. Loki reports that a vari-speed belt massager is easily converted into a high powered laboratory shaker. Another old route to nitroethane is described in Industrial and Engineering Chemistry, Vol. 28,March 1936 pp 339=344. This method involves vapor phase nitration of paraffins, producing 26% nitroethane from propane, and at least 80% from ethane. In essence the procedure bubbles the paraffin gas through nitric acid heated to 108 degrees centrigrade. The gaseous mixture is then led through a reactor heated to 420 degrees centrigrade, condensed, and fractionated. In the article, Hass et al state that superatmospheric pressure increased the yield somewhat, and that aluminum nitrate, glass, and stainless steel produced no catalytic effect. Silica gel and platinum promoted oxidation instead of nitration. If an effective catalyst could be found, a simple tube furnace could be substituted for the eutetic salt heated tubing reactor. Perhaps some members of the Hive with easy access to a real chemistry library could research nitration catalysts.



Ritter (Member) 07-27-99 01:47 No 103082	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	The simplest and highest yielding procedure to hit the underground literature is posted in TSII by yours truly. The method uses phloroglucinol to scavenge detrimental nitrous compounds during the Sn2 rctn. between NaNO2 and an alkyl halide in a polar aprotic solvent. A post showed up a few months ago here on the boards describing the failure of NaNO2 and ethyl bromide in a polar aprotic solvent (DMF,DMSO and n-Methylpyrolidinone) to form nitroethane. I must reccomend my synthesis over any dealing with diethylsulfate due to the inherently poisonous nature of this nasty chemical warfare agent. Face it, ordering any hazardous chemicals let alone known poisons is a risk. People must realize that a whole new governmental agency is being added to the loop of hazards involved w/ obtaing needed reagents. The DOT is made aware of each and every shipment of those boxes with the pretty rotated square placard sticker stickers which say things like corrosive, poison, reactive w/ water, dangerous-you get the idea. Diethyl sulfate is such a toxic material that inquiries may be made over why such a toxic material was requested by a venue. Ritters nitroethane synth is by far the best because ordering needed ragents will not arouse suspicion for any reason. You sure can't say that about diethylsulfate. The only drawback from the described synth is the price of phloroglucinol, however a simple NaOH wash of the rctn products will separate all glucinol to allow regeneration for another batch. It can be used over and over. This method often yields over 90% and literature citings are provided to back these claims. Check it out!



ymir (Member) 07-27-99 04:49 No 103083	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Phlorglucinol is prepared by fusion of resorcinol with caustic soda and decomposition of the melt with acid. Since phlorglucinol is over five times as expensive as resorcinol, some bees may prefer to make it. Most uses are medical. Few procedures are benign enough to be performed in the kitchen, most require a laboratory quality fume hood and or glove box. Diethyl sulfate is very toxic and hazardous, and should be handled in a hood with gloves.



Osmium (Moderator) 07-27-99 05:44 No 103084	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Don't think that wearing rubber gloves will protect you whatever happens. Once that shit is spilled over the gloves, it's time to change and discard them. NOW! Not in 2hrs, now! This is true for most other solvents and chems. You can't put your gloved hand into a barrel of stuff and expect them not to leak after a few seconds. Don't want to frighten anybody, but that's the way it is. Wearing gloves does not mean you are safe and can do whatever you want!



Alchemy (Member) 07-27-99 06:49 No 103085	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Hi If Sodium Nitrite is controled where You live(carcinogen) there is a good method from sodiumnitate and Pb(lead) described in W.T.Cooke "The Laboratory Preparation of Sodium Nitrite" Australian chem. Inst. J Proc. Vol.11(1944)49-51 Sincerely Alchemy



Snotbrain (Member) 07-27-99 19:18 No 103086	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Just a small note to these procedings: A great, variable shaker can be obtained from the use of the water bed vibrators, or the gizmoes that vibrate your bed for 25 cents in cheap motels. Not that I've ever been in any cheap motels: I'm way to classy for that. (Yeahrite) Two variable speed vibrators can make the old oscillating sander trick look pretty tame: as you adjust their harmonic interactions! snodder



spitball (Moderator) 07-27-99 19:40 No 103087	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Goddammit! I've been looking for a bed vibrator for years! Where,son, where did you find such an awesome commodity???? -spitball- oh, and another thing that the fabulous Rev.Drone envisioned, was using one of those 'fat jigglers' from the 50's - 60's( you know, the belts on the machnine that shakes you back and forth?) to vibrate a large vessel...



ymir (Member) 07-27-99 19:57 No 103088	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Industrial quality gloves are needed for things like diethyl sulfate. North makes a good product. It turns out that if phenol is fused with caustic soda; pyrocatchetol, resorcinol and phlorglucinol are formed (Ber. 12, 417 Post No 1879). After seperation, the pyrocatchetol is saved for future use(see TSII for details), the resorcinol is fused with caustic soda, and acidified, producing more phlorglucinol. Phenol(carbolic acid) is very cheap and easily available. A large crucible would be helpful in this matter, though there may be substitutes. Separation could be a problem, Loki wonders if column chromatography might be superior to fractional distillation. Also, use of a tube furnace doesn't appear to be a good idea for vapor-phase nitration. The reaction is exothermic, and works best at the higher operating temperature. Contact time can be as little as a fraction of second at the higher temperatures. An excess of the hydrocarbon is used to serve as a heat sink to prevent explosions. Catalysts used are oxygen and bromine/chlorine, with the nitric acid/oxygen/bromine molar ratio being 1/2/.003. Those who are interested should look at JOC 17, 906-944 for more info. While this method is certainly the cheapest in terms of materials (propane!), the equipment could be very expensive, unless fabricated by a MacGyver type. The diethyl sulfate/sodium nitrite method would be second cheapest as far as materials, not as equipment intensive (Loki thinks he could hook up 4 gallon jugs to his shaker!) as vapor phase nitration, but involve a very hazardous material, and some obnoxious by products as well (nitrous acid and nitrite esters venting). Ritter's related method is not nearly as expensive as it first sounds, with phenol costing around $75/gal. If the total yield was only around 25%, that would still make it about $100/kg, far less than it sells for. For the average chemist, Ritter's method looks to be the best.



Snotbrain (Member) 07-28-99 17:19 No 103089	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Youse can dredge them up at a waterbed store for about $30 bux. Damn: even FINDING a waterbed store these days is trick: seems to be a vanishing commodity. snodder



ymir (Member) 07-28-99 18:41 No 103090	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Organic Reactions 12, p 110 reveals an interesting fact about the sodium nitrite/alkyl halide synthesis of nitroparaffins: catechol and resorcinol share the nitrite ester scavenging effect of phlorglucinol. Obviously, this means that in the synthesis in Ber. 11, 1332(1878) & 12, 417 (1879) which produces these three compounds from phenol, purification is probably not absolutely necessary. Kornblum (JACS 78, 1497-1501) reports that colored impurties result when these two compounds are used, and also that ethylene glycol can work as a solvent. Perhaps something as simple as Norit could remove these impurities. Nitroparaffins were purified by Pearson for use in kinetic studies by drying with magnesium sulfate, refluxing with urea, drying with phosphorus pentoxide, and distillation through a 10-plate column. Turnbull and Maron purified nitroparaffins by treatment with urea, sodium sulfate, and low temperature distillation. The vapor phase nitration has been done in small diameter tube reactors, fluidized bed reactors, and molten salt reactors according to Kirk-Othmeyer. No specific reference is given for the tube reactors, further library investigation is needed.



ymir (Member) 07-29-99 06:48 No 103092	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	My mama, like all bees! What the bees, or almost all other scientists for that matter, don't realize is the importance of 'old' chemistry. This science, for all practical purposes, began in Germany several hundred years ago. If this is hard to believe, just consider the terminology: Fischer projection, Bunsen burner, Liebig condenser and Erlenmeyer flask. The rest of the world followed suit. Thus a search for the truth must include searching all windows to the literature. Some very fine general works of reference have been published over the years, such as Kirk-Othmeyer and Thorpe's. Now, new science is very interesting and useful, but old science can be applied to current problems that didn't exist when it was published. Certainly, Drone's idea about using PTC catalysts may be very useful in this matter. Experimentation by those with the proper equipment is required to determine the truth! Ethylene glycol will probably not be as good as a solvent as DMSO/DMF, and will require the use of urea, but it, along with phlorglucinol synthesis from phenol, does allow for cost effective scalability. It seems that that these three paths will make piperonal more useful, as making black pepper a controlled substance might not wash with the public. As more and more paths become known, the sooner the control freaks will be overthrown!



Ritter (Member) 07-29-99 12:18 No 103091	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Ymir, Where did you come from anyway? Your posts are always meticulously researched and have helped many here! We greatly appreciate all the time and effort you devote to researching all of these amazing references! Thanks so much for all of your input!!!!!!!!!!!! Ritter



ymir (Member) 07-31-99 18:42 No 103093	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	The reference in which a small diameter aluminum tubular reactor was used to nitrate paraffins is Chem. Eng. 73,(12) 149 (1966). Pressures between 8 and 12 atmospheres are most effective. Any catalyst would have to promote the free radical reaction mechanism. Some references not given already are JACS 62, 2885 (1936) & 66 2017(1944) and Ind. Eng. Chem. 30, 67(1938); 31, 648(1939); 32, 427(1940); 34, 400(1942) & 41, 2266(1949). In the alkyl halide method(modified Meyer synthesis), urea is used to increase the solubility of sodium nitrite. Ethylene glycol is inferior as a solvent, but can be made to work. This reaction, and the related methods based on sodium ethyl sulfate, both work as a nucleophilic replacement at carbon by nitrite. Any experiments with phase transfer catalysts would have to be compatible with this reaction mechanism. One thing that should be obvious, but apparently isn't is the use of the nitrite ester scavanging phlorglucinol with the diethyl sulphate/sodium nitrite reaction. Both of these reactions work by the same mechanism, and ester formation needs to be suppressed to maximize yield. This may well increase the yield of the synthesis that this thread was started about.



rev drone (Member) 07-31-99 19:19 No 103094	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Hm, a heated, 8-12 atm vapor phase nitration of ethane? Doesn't that strike you as a tad impractical? I must say, even with the extensive resources that some of the elite bees here have, I could not see a "clandustrial" application utiizing such conditions any time in the near future. Ho-hum; perhaps Ritter's method is best, though I still don't see any advantage in ethyl bromide over diethyl sulfate. Ethyl bromide is poisonous, carbinogenic, and will arrive at your door with just as many HazMat stickers. I agree EtBr's smell is MUCH nicer, but both of them should only be used under a fume hood. I never heard of diethyl sulfate being used as a chemical warfare agent. This is a major industrial chemical; there's nothing obscure about it. Then again, during WWI they threw everything but the kitchen sink at each other. ------------------ -the good reverend drone



ymir (Member) 07-31-99 19:36 No 103095	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Actually, these references are about nitration of propane, resulting in a mixture of nitroparaffins, including nitromethane and nitroethane. Propane is really inexpensive. Definitely not for the average chemist, but for those with the McGyver animus...



Rhodium (Chief Bee) 11-17-01 18:17 No 237884	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	This sounds like an interesting thread. I ESPECIALLY would like someone to fetch the reference mentioned in Alchemy: "Re: What can be done to improve the performance of clandestine nitroethane synth? " (Chemistry Discourse).



Aurelius (Hive Bee) 11-18-01 15:13 No 238118	Re: What can be done to improve the performance of clandestine nitroethane synth? (Rated as: excellent)	Bookmark Reply
	here's what available on the hive, thus far: Nitroethane synthesis: a compilation Method 1: from sodium ethyl sulfate and a metal nitrite 1.5 mole sodium nitrite (103.5g) is intimately mixed with 1 mole of sodium ethyl sulfate (158g) and 0.0625 moles of K2CO3 (8.6g). The mixture is then heated to 125-130°C, at which temperature the nitroethane distills over as soon as it is formed. The heating is discontinued when the distillation flow slackens considerably, and the crude nitroethane is washed with an equal amount of water, dried over CaCl2, and if needed, decolorized with a little activated carbon. The nitroethane is then re-distilled, collecting the fraction between 114-116°C. Yield 46% of theory (another ref says max. 42%) Chemical Abstracts, Vol 49, pg 836. Method 2: from diethyl sulfate and sodium nitrite Initial run - Into a stoppered bottle was placed a mixture of diethyl sulfate (120g) and sodium nitrite solution (120g in 160ml of water.) The bottle was shaken mechanically for 20 hours, the pressure being released at intervals. The contents were then poured into a separating funnel, and the upper layer separated, dried over calcium chloride. and distilled at 14 mmHg, the distillate up to 60°C being collected (the residue, ca. 230g., consisted of ethyl sulphate and was used again). The distillate was fractionated at atmospheric pressure, and the fraction of bp 114-116°C collected. This was shaken with water, dried over calcium chloride, run through charcoal, and redistilled; bp 114-115.5°C. Yield, 17.7g. (31%, or allowing for recovered ethyl sulfate, 43.5%). Routine run - A second experiment was then carried out using the same quantity of ethyl sulfate as above. The recovered nitrite solution (lower layer) from the first run was concentrated by adding approximately 16 g. of sodium nitrite per 160ml of solution. Yield 26.4g (46%, or allowing for recovered ethyl sulphate, 65%). For each additional subsequent run approximately 16 g. of nitrite per 160 ml of solution were added, although this represents a rather diminishing concentration in view of the increased yield of nitroethane Method 3: from ethyl bromide (iodide) and sodium nitrite (dmf) 32.5 grams of ethyl bromide (0.3 moles) was poured into a stirred solution of 600ml dimethylformamide and 36 grams dry NaNO2 (0.52 mole) in a beaker standing in a water bath keeping the solution at room temperature as the reaction is slightly exothermic. Always keep the solution out of direct sunlight. The stirring was continued for six hours. After that, the reaction mixture was poured into a 2500 ml beaker or flask, containing 1500 ml ice-water and 100 ml of petroleum ether. The petroleum ether layer was poured off and saved, and the aqueous phase was extracted four more times with 100 ml of petroleum ether each, where after the organic extracts were pooled, and in turn was washed with 4x75ml of water. The remaining organic phase was dried over magnesium sulfate, filtered, and the petroleum ether was removed by distillation under reduced pressure on a water bath, which temperature was allowed to slowly rise to about 65°C. The residue, consisting of crude nitroethane was distilled under ordinary pressure (preferably with a small distillation column) to give 60% of product, boiling at 114-116°C. The ethyl bromide reacts with NaNO2, forming nitroethane and ethyl nitrite. This method can be varied in a few ways. Firstly, dimethyl sulfoxide (DMSO) can be substituted for the dimethylformamide (DMF) as solvent. Ethylene glycol also works as solvent, but the reaction proceeds pretty sluggishly in this medium, allowing for side reactions, such as this: RH-NO2 + R-ONO => R-(NO)NO2 + R-OH. KNO2 can also be used instead of NaNO2. If NaNO2 is used in DMF, 30g (0.5 mol) of urea can also be added as nitrite scavenger to minimize side reactions, as well as simultaneously increasing the solubility of the NaNO2 and thereby significantly speeding up the reaction. If the ethyl bromide is substituted with ethyl iodide, the required reaction time is decreased to only 2.5 h instead of 6 h. In case ethyl iodide is employed, a slight change in the above procedure needs to be done. The pooled pet ether extracts should be washed with 2x75ml 10% sodium thiosulfate, followed by 2x75ml water, instead of 4x75ml water as above. This to remove small amounts of free iodine Method 4 : from ethyl halide and silver nitrite Cool 100 g of silver nitrite (0.65 mol) in 150 ml of dry ether to 0°C in a 3 neck 500 ml flask (in a darkened room or using yellow light). Add 0.5 moles of ethyl halide (78g ethyl iodide or 55g of ethyl bromide) dropwise over a 2 hour period while stirring constantly and maintaining the temperature at 0°C and dark conditions. Stir for 24 hours at 0°C, then 24 hours at room temp if using ethyl bromide, and 48h if using ethyl bromide. (Test for halogens to see when the reaction is completed, through adding a few drops of the reaction mixture to a test tube containing an alcoholic solution of silver nitrate and note if a precipitate appears. If so, the reaction is not complete. The Beilstein test can also be used, it uses a small coil of copper wire in a test tube to which a small portion of the reaction mixture is added and it is noted if reaction occurs, where elemental silver will deposit on the surface of the copper coil.) Silver iodide (or bromide) will precipitate in the solution during the course of the reaction. Filter off the silver salt, and wash it with several portions of ether. Evaporate the ether at room temperature. (This may be substituted with distillation of the ether using a water bath at atmospheric pressure. A 2x45 cm column packed with 4 mm pyrex helices is used. A more efficient column is not used due to the instability of the ethyl nitrite formed as a by-product in the reaction. Maintain anhydrous conditions since the ethyl nitrite will hydrolyze to ethanol and will be difficult to separate.) Then vacuum distill the residue at about 5 mmHg. The ethyl nitrite will be the initial fraction, followed by an intermediate fraction, then the nitroethane will distill. The yield is about 83% of theory Method 5: oxidation of ethyl amine with peracids (m-perbenzoicacid) General Procedure for the Oxidation of Primary & Secondary amines using m-chloroperbenzoic acid. m-Chloroperbenzoic acid (4.1g, 0.02mol, 85% pure) is dissloved in 30 mls of 1,2-dichloroethane in a three-neck flask equipped with a condenser and a pressure-equalising dropping funnel. The amine (0.005 mol) in 3-5 mls of 1,2-dichloroethane solvent is added drop-wize to the refluxing m-Chloroperbenzoic acid/1,2-dichloroethane solution. Refluxing temperature 83oC for 3 hours. After the addition of the amine and refluxing time, the reaction mixture is cooled, filtered and washed with three 50 ml portions of 1M sodium hydroxide solution and dried over anhydrous magnesium sulphate. The removal of the 1,2-dichloroethane solvent by distillation (rotary) gives a crude nitroalkane. Purification of the crude crude nitroalkane with vacuum distillation. Yields vary, approx 62 %. Oxidation of n-propylamine and higher alkane amines give nitroalkane at approx 62 %. [Note] Nitromethane and nitroethane form sodium water-soluable salts with 1M sodium hydroxide solution Method 6: oxidation of ethyl amine with potassium permanganate Perhaps by the method in Org Synth CV 5, 845. REFS for methods 5 + 6: Chem.Ber. (1902) 35, 4294 Eur.J.Med.Chem. (1991) 26, 2, 167-178 Eur.J.Org.Chem. (1998) 4, 679-682 Heterocycles (1998) 48, 1, 181-185 J.Amer.Chem.Soc. (1954) 76, 4494 J.Amer.Chem.Soc. (1956) 78, 4003 J.Amer.Chem.Soc. (1957) 79, 5528 J.Chem.Soc.Chem.Commun. (1995) 15, 1523-1524 J.Org.Chem. (1960) 25, 2114-2126 J.Org.Chem. (1979) 44, 659-661. J.Org.Chem. (1992) 57, 25, 6759-6764 J.Org.Chem. (1993) 58, 5, 1118-1121 Magn.Reson.Chem. (1997) 35, 2, 131-140 Org.Synth. (1963) 43, 87 Tetrahedron (1991) 47, 28, 5173-5184 Tetrahedron (1995) 51, 41, 11305-11318 Tetrahedron Lett. (1981) 22, 18, 1655-1656 Tetrahedron Lett. (1986) 27, 21, 2335-2336 Tetrahedron Lett. (1996) 37, 6, 805-808 Z.Naturforsch.B (1989) 44, 11, 1475-1478 Method 7: destructive distillation of alpha-bromopropionic acid with sodium nitrite K2CO3 + NaNO2 + H2O + a-br-propionic acid à nitroethane 50%yield Add 20g of the acid to a solution of K2CO3 in the amount of base that causes the solution to be basic to phenolphthalein. The add 20g of NaNO2—there should be approx. 100ml of solution. Place in a 250ml rb flask and distill quickly- the first 100ml will come over before the rxn takes place. Then the nitroethane comes over. Distill until no more product comes over. (don’t distill to dryness) V. Auger. Bull. Soc. Chim. France Post no. 3, 23, 333 (1900) by the kolbe method. Method 8: oxidation of ethyl amine to nitroethane with dimethyldioxirane A new synthesis of nitro compounds using dimethyldioxirane(DMDO) Tetrahedron Letters,Vol.27,No.21,pp 2335-2336,1986 Abstract: Dimethyldioxirane oxidizes primary amines to nitro compounds in a facile, mild, high yield process. Here we report that aliphatic and aromatic primary amines are rapidly and efficiently oxidized to nitro compounds by dimethyldioxirane, DMDO. Indeed a survey of some general methods for the preparation of nitro compounds (2) suggests to us that the use of DMDO may be the method of choice. The conditions used are exceedingly mild and give the nitro compound as a solution in acetone. Table 1 summarizes our results with some representative amines. Table 1. Oxidation of amines with Dimethyldioxirane(DMDO). Amine Product Yield (Product m.p.(C) ~~~~~~~~~~~~~~~~~~~~~~~--~~~~~~--~---~~~~~~~~~~~-- Aniline Nitrobenzene 91 p-Anisidine p-Nitroanisole 94 54 n-Butylamine 1-Nitrobutane 84 sec-Butylamine 2-Nitrobutane 81 tert-Butylamine 2-Methyl-2-nitrobut 90 1-Aminoadamantane 1-Nitroadamsntane 95 159 Cyclohexylamine Nitrocyclohexane 95 trans-Azobenzene Axoxybenzene 96 36 In a typical reaction n-butylamine (0.052g; 0.7 mmol) in 5 ml of acetone was treated with 95 ml of DMDO, in acetone solution (ca 0.05M)(4) The solution was kept at room temperature for 30 min. with the exclusion of light. Analysis of the reaction mixture by capillary GC indicated the presence of l-nitrobutane only. The oxidations are believed to occur by means of successive oxidations by,1. In the aniline case the blue color of the nitroso conpound is observed immediately upon adding the solution of DMDO. In separate experiments we have shown that both phenylhydroxylamine and nitrosobenzene are readily oxidized to nitrobenzene by DMDO. The blue color of intermediate nitroso compound was observed in all of the amine oxidations. Dimethyldioxirane is a powerful oxygen atom donor, which oxidizes a variety of substrates 'including hydrocarbons'. Work is continuing on the oxidation of nitrogen-containing compounds by DMDO. 1. Chemistry of Dioxiranes. 5. Paper 4 of this series is J. Am. Chem. Soc., in press (1986). 2. H.O. Larson in The Chemistry of the Nitro and Nitroso Groups, H. Feuer, Ed., J. Wiley and Sons. N.Y. 1969. 4. The concentration of,DMDO in acetone was determined by titrating an aliquot with phenyl methyl sulfide. The synthesis of DMDO has been described (5). 5. R.W. Murray and R. Jeyaraman, J. Org. Chem., (50) 2847 (1985). Dioxiranes: synthesis and reactions of methyldioxiranes. J. Org. Chem. (1985), 50(16), 2847-53. Abstract The peroxymonosulfate-acetone system produces dimethyldioxirane under conditions permitting distn. of the dioxirane from the synthesis vessel. The same conditions were used to prep. other methyldioxiranes. Solns. of dimethyldioxirane prepd. in this manner were used to study its chem. and spectroscopic properties. The caroate-acetone system was also used to study the chem. of in situ generated dimethyldioxirane. cis- And trans-stilbenes were converted stereospecifically to the corresponding epoxides with dimethyldioxirane in acetone Method 9: isomerization of ethyl nitrite to nitroethane over asbestos catalyst J. Chem. Soc. 109, 701 (1916) (pass over asbestos in a tube furnace @ 120-130C for best results/best yield) Method 10: ethyl bromide, DMSO, NaNO2 and phloroglucinol dihydrate By Ritter, in Strike’s book- TSII. 32g or 26ml EtBr is poured into 250ml of DMSO with 36g NaNO2 and 52g phloroglucinol already present in solution. (Pglucinol is expensive but can be recycled) put on good mag. stirring and stopper the flask. Stir for two hours in emulsion form, then dump into a 600ml of ice water and extract twice with DCM. (2x200ml) dry the extracts with MgSO4 or CaCl2 the evap off the DCM. Distill and collect the fraction from 113-116C--- yields about 20g of nitroethane (80%) (another ref say maybe over 90% consistently) Other notes: catechol and resorcinol have the same nitrite scavenging abilities as phloroglucinol. And ethylene glycol can be used as a solvent. A simple NaOH wash of the final solution (nitroethane removed) will give the sodium salt of your phloroglucinol catalyst. Acidification of the solution will precip the catalyst for recovery by filtration. JACS 79, 2507 (1957) Tetrahedron vol 46, No 21, pp 7443-57 (1990) Ber. 11, 1332 (1878) Ber. 12, 417 (1879) JACS, Vol 78, 1497-1501 Method 11: 3-chloropropionic acid sodium salt, and NaNO2 ClCH2CH2COONa + NaNO2 à NO2CH2CH2COONa + NaCl NO2CH2CH2COONa + H2O –heatà NO2CH2CH3 + NaHCO3 Modification of Nitromethane synthesis from Organic Synthesis, Vol? Pg 401. Method 12: most complicated synth CH3CH=NOH + Cl2 à CH3CH (Cl)(NO) (ß gem-chloronitrosoethane) Gem-comp + O3 à CH3CH (Cl)(NO2) CH3CH (Cl)(NO2) + NaOH + H2 + Pd/C à nitroethane (50%) + HCl JOCS, Vol 41, pg 733-735 (1976) Method 13: electrochemical oxidation ---- not possible by method below Ethyl amine is oxidized to methyl nitrile in anhydrous solvent. In the presence of water it is oxidized to the imine, then acetaldehyde which is further oxidized to acetic acid. Method 14: Vapor Phase nitration of propane. The propane is bubbled through nitric acid heated to 108C and lead into a reactor at 420C. the product is then condensed and fractionated. (26% nitroethane formed) Industrial and Engineering Chemistry, Vol 28, Mar, 1936. Pg 339-344. JOC, Vol 17, pg 906-944. Method 15: Vapor Phase nitration of ethane. Same as propane but at least 80% yields. Industrial and Engineering Chemistry, Vol 28, Mar, 1936. Pg 339-344. JOC, Vol 17, pg 906-944. Method 16: Vapor Phase Nitration of Ethanol using Group II oxides or halides as a catalyst (works for methanol and propanol too) US pat # 4431842 Method 17: Distillation of alpha-bromopropionic acids with NaNO2 in the presence of Magnesium Sulfate in DMSO US pat # 4319059 (the alpha-bromo acid can be obtained using propionic acid in the procedure from Org. Synth. CV 1, 115.) Method 18: Oxidation of alanine with permanganate followed by decarboxylation Nitroethane via oxidation of alanine? Theory ------ MeCH(NH2).COOH + 3(O) --> MeCH(NO2).COOH + H2O. MeCH(NO2).COOH + NaOH --> MeCH(NO2).COONa. MeCH(NO2).COONa + H2O --> MeCH2(NO2) + NaHCO3. Procedure --------- A solution of potassium permanganate (0.3 mol) in water was made by dissolving 47.41 g KMnO4 in 400 mL hot water in a 1 L 3-necked flask fitted with a reflux condenser, a stirbar[note 1], thermometer, and a 100-mL addition funnel. As the solution cools to room temperature fine crystals of KMnO4 crystallise out of solution[note 2]. A solution of alanine (0.1 mol, 8.91 g) in 65 mL of water was placed in the addition funnel and added dropwise with stirring over a 20 minute period. The temperature slowly rose. When the addition was complete, the reaction mixture was heated to 60º over a period of approximately 2 hours. 40 mL of acetone was added [note 3] and then the reaction mixture maintained at 70-85º [the sludge was extremely viscous and the stirbar was of no use] for 2 hours. 0.1 mol sodium hydroxide in 20 mL of water was then added through the addition funnel. Pause (to be completed). ----- The flask showed no sign of heating up after addition of the NaOH. By now the black/brown sludge will not mix (with the stir-bar). The next step is to heat to 80-100C to decarboxylate any nitro-propionic acid and then to steam distil. Notes: ------ 1. An overhead stirrer is essential - the stirbar will get clogged with MnO2. 2. KMnO4 solubility is 1 in 3.5 parts of hot water and 1 in 14 parts of cold water. 3. The acetone was added to try to clear the sludge. I would have added more but I had second thoughts. Refs: 1. Synthesis Of Aliphatic And Alicyclic Nitro Compounds; Org. Syn. p 131-132 [The Oxidation of Amines] 2. Organic Syntheses, Vol. 52, pp 77-82, 2-Metryl-2-Nitrosopropane and its Dimer, A. Calder, A. R. Forrester and S. P. Hepburn. 3. Vogel's Practical Organic Chemistry, 4th ed. P 564 'Nitromethane'. Questions. ---------- 1. Is it safe to heat this mixture to 90C without a stirrer? [the next step to make sure that nitro-propionic acid is decarboxylated] 2. Should I improvise an overhead stirrer to finish this off? 3. Nitroethane will steam distil won't it? 4. Should the permanganate have been buffered? 5. I think the NaOH should have been in there from the start. The sodium salt of alanine would have been a better idea? 6a. Would the reaction benefit from taking place in an organic solvent? 6b. If so, what solvents are suitable apart from acetone? I will repeat this - with an overhead stirrer and the addition of sodium salt of alanine rather than alanine followed by NaOH. Method 19: Reduction of acetaldehyde oxime and oxidation of the product Good work ! An alternative method to alanine amino oxidation and decarboxylation is the reaction : CH3CHO + NH2OH ==>> CH3CH=NOH, Then carfully reduced to CH3CH2NHOH, and then oxidized as proposed by you above to get CH3CH2NO



Osmium (Stoni's sexual toy) 11-18-01 15:26 No 238123	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Rearrangement of ethyl nitrite.



Aurelius (Hive Bee) 11-18-01 15:37 No 238126	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	BTW, Rhodium, you can place all those synths as a nitroethane FAQ- it's not quite complete, but with a little help, aurelius can complete it. mostly, aurelius just lacks access to a few of the articles. that and everything that's available on the hive and your site for nitroethane is on this so far. (if aurelius missed something, please tell aurelius so it can be included)



joyman (Newbee) 11-18-01 15:42 No 238127	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Method 11: 3-chloropropionic acid sodium salt, and NaNO2 ClCH2CH2COONa + NaNO2 „³ NO2CH2CH2COONa + NaCl NO2CH2CH2COONa + H2O ¡Vheat„³ NO2CH2CH3 + NaHCO3 Modification of Nitromethane synthesis from Organic Synthesis, Vol? Pg 401. WizardX mentioned this a couple of times but didn't give the full reference - heres the ref. From Organic Syntheses, Collective Vol. I, pp 401-403, To 500 g of chloroacetic acid in 500 g cracked ice add enough 40% NaOH solution to make the resulting mixture slightly alkaline. Do not let the temperature rise above 20 degrees C. This solution is mixed with 365 g sodium nitrite dissolved in 500 ml water in a 3 liter round-bottom flask. This flask should then be equipped with a thermometer dipping into the liquid and a distillation condenser. The mixture is carefully heated until the first bubbles or carbon dioxide appear (at about 80 C). The heat is then withdrawn and the heat of the reaction keeps it warm. If the reaction becomes too vigorous, it should be cooled. After the reaction ceases, heat cautiously until 110 C is reached. Nitromethane will distill over during this heating and the previous spontaneous heating. Separation of the nitromethane / water mixture and redistillation will give approx. 35 % yield after drying and redistillation.



Aurelius (Hive Bee) 11-18-01 15:57 No 238131	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Joyman, your the greatest. thanks Marcus



Antoncho (Official Hive Translator) 11-18-01 19:15 No 238213	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Ethyl nitrite rearrangement doesn't work (at least, for any practical purpose). If you carefully read the original article you'll see why - the rate of convertion is way too slow . Antoncho



Aurelius (Hive Bee) 11-18-01 22:06 No 238281	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	ok, aurelius is just collecting what's been posted through the years. would somebody please state whether the ethyl nitrite route is rearrangement, isomerization or whatever. the article (at least) is correct. aurelius would like somebody (Antoncho-who has obviously seen the article) to post the article so that the rest can observe and aurelius can perhaps remove that method or include its experimental portions.



Aurelius (Hive Bee) 11-18-01 22:46 No 238291	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	some stuff from a while back on the hive rev drone It makes sense. Thermodynamically, this is quite favorable. But the only references I can find to the isomerization of lower alkyl nitrites into lower nitoalkanes involve considerable heat and pressure -- not to mention the occasional asbestos catalyst. So does anybody have any good ideas about any magical transition metal catalysts that could facilitate isomerization at more ambient conditions? It looks so good, so obtainable, yet somehow its so out-of reach. ------------------ -the good reverend drone Ipsa scientia potestas est Chem Guy Not Fe, that's for sure. Intutively, I would say Lewis acid catalyzed rearrangement, but that is only a whim. I don't know for sure. Acme My magic 8-ball came up blank on this one. I asked it (reactant)GH-CH2-CH2-O-N-O --->> (product)GH-CH2-CH2-NO2 and big fat goose egg was the reply, sadly Osmium Share the refs you already have Drone. I've never heard something like that rev drone J.Chem.Soc.; 109; 1916; 701; ------------------ -the good reverend drone Ipsa scientia potestas est



Aurelius (Hive Bee) 11-19-01 00:24 No 238307	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	Here's the updated list: Nitroethane synthesis: a compilation Method 1: from sodium ethyl sulfate and a metal nitrite 1.5 mole sodium nitrite (103.5g) is intimately mixed with 1 mole of sodium ethyl sulfate (158g) and 0.0625 moles of K2CO3 (8.6g). The mixture is then heated to 125-130°C, at which temperature the nitroethane distills over as soon as it is formed. The heating is discontinued when the distillation flow slackens considerably, and the crude nitroethane is washed with an equal amount of water, dried over CaCl2, and if needed, decolorized with a little activated carbon. The nitroethane is then re-distilled, collecting the fraction between 114-116°C. Yield 46% of theory (another ref says max. 42%) Chemical Abstracts, Vol 49, pg 836. Method 2: from diethyl sulfate and sodium nitrite Initial run - Into a stoppered bottle was placed a mixture of diethyl sulfate (120g) and sodium nitrite solution (120g in 160ml of water.) The bottle was shaken mechanically for 20 hours, the pressure being released at intervals. The contents were then poured into a separating funnel, and the upper layer separated, dried over calcium chloride. and distilled at 14 mmHg, the distillate up to 60°C being collected (the residue, ca. 230g., consisted of ethyl sulphate and was used again). The distillate was fractionated at atmospheric pressure, and the fraction of bp 114-116°C collected. This was shaken with water, dried over calcium chloride, run through charcoal, and redistilled; bp 114-115.5°C. Yield, 17.7g. (31%, or allowing for recovered ethyl sulfate, 43.5%). Routine run - A second experiment was then carried out using the same quantity of ethyl sulfate as above. The recovered nitrite solution (lower layer) from the first run was concentrated by adding approximately 16 g. of sodium nitrite per 160ml of solution. Yield 26.4g (46%, or allowing for recovered ethyl sulphate, 65%). For each additional subsequent run approximately 16 g. of nitrite per 160 ml of solution were added, although this represents a rather diminishing concentration in view of the increased yield of nitroethane Method 3: from ethyl bromide (iodide) and sodium nitrite (dmf) 32.5 grams of ethyl bromide (0.3 moles) was poured into a stirred solution of 600ml dimethylformamide and 36 grams dry NaNO2 (0.52 mole) in a beaker standing in a water bath keeping the solution at room temperature as the reaction is slightly exothermic. Always keep the solution out of direct sunlight. The stirring was continued for six hours. After that, the reaction mixture was poured into a 2500 ml beaker or flask, containing 1500 ml ice-water and 100 ml of petroleum ether. The petroleum ether layer was poured off and saved, and the aqueous phase was extracted four more times with 100 ml of petroleum ether each, where after the organic extracts were pooled, and in turn was washed with 4x75ml of water. The remaining organic phase was dried over magnesium sulfate, filtered, and the petroleum ether was removed by distillation under reduced pressure on a water bath, which temperature was allowed to slowly rise to about 65°C. The residue, consisting of crude nitroethane was distilled under ordinary pressure (preferably with a small distillation column) to give 60% of product, boiling at 114-116°C. The ethyl bromide reacts with NaNO2, forming nitroethane and ethyl nitrite. This method can be varied in a few ways. Firstly, dimethyl sulfoxide (DMSO) can be substituted for the dimethylformamide (DMF) as solvent. Ethylene glycol also works as solvent, but the reaction proceeds pretty sluggishly in this medium, allowing for side reactions, such as this: RH-NO2 + R-ONO => R-(NO)NO2 + R-OH. KNO2 can also be used instead of NaNO2. If NaNO2 is used in DMF, 30g (0.5 mol) of urea can also be added as nitrite scavenger to minimize side reactions, as well as simultaneously increasing the solubility of the NaNO2 and thereby significantly speeding up the reaction. If the ethyl bromide is substituted with ethyl iodide, the required reaction time is decreased to only 2.5 h instead of 6 h. In case ethyl iodide is employed, a slight change in the above procedure needs to be done. The pooled pet ether extracts should be washed with 2x75ml 10% sodium thiosulfate, followed by 2x75ml water, instead of 4x75ml water as above. This to remove small amounts of free iodine Method 4 : from ethyl halide and silver nitrite Cool 100 g of silver nitrite (0.65 mol) in 150 ml of dry ether to 0°C in a 3 neck 500 ml flask (in a darkened room or using yellow light). Add 0.5 moles of ethyl halide (78g ethyl iodide or 55g of ethyl bromide) dropwise over a 2 hour period while stirring constantly and maintaining the temperature at 0°C and dark conditions. Stir for 24 hours at 0°C, then 24 hours at room temp if using ethyl bromide, and 48h if using ethyl bromide. (Test for halogens to see when the reaction is completed, through adding a few drops of the reaction mixture to a test tube containing an alcoholic solution of silver nitrate and note if a precipitate appears. If so, the reaction is not complete. The Beilstein test can also be used, it uses a small coil of copper wire in a test tube to which a small portion of the reaction mixture is added and it is noted if reaction occurs, where elemental silver will deposit on the surface of the copper coil.) Silver iodide (or bromide) will precipitate in the solution during the course of the reaction. Filter off the silver salt, and wash it with several portions of ether. Evaporate the ether at room temperature. (This may be substituted with distillation of the ether using a water bath at atmospheric pressure. A 2x45 cm column packed with 4 mm pyrex helices is used. A more efficient column is not used due to the instability of the ethyl nitrite formed as a by-product in the reaction. Maintain anhydrous conditions since the ethyl nitrite will hydrolyze to ethanol and will be difficult to separate.) Then vacuum distill the residue at about 5 mmHg. The ethyl nitrite will be the initial fraction, followed by an intermediate fraction, then the nitroethane will distill. The yield is about 83% of theory Method 5: oxidation of ethyl amine with peracids (m-perbenzoicacid) General Procedure for the Oxidation of Primary & Secondary amines using m-chloroperbenzoic acid. m-Chloroperbenzoic acid (4.1g, 0.02mol, 85% pure) is dissloved in 30 mls of 1,2-dichloroethane in a three-neck flask equipped with a condenser and a pressure-equalising dropping funnel. The amine (0.005 mol) in 3-5 mls of 1,2-dichloroethane solvent is added drop-wize to the refluxing m-Chloroperbenzoic acid/1,2-dichloroethane solution. Refluxing temperature 83oC for 3 hours. After the addition of the amine and refluxing time, the reaction mixture is cooled, filtered and washed with three 50 ml portions of 1M sodium hydroxide solution and dried over anhydrous magnesium sulphate. The removal of the 1,2-dichloroethane solvent by distillation (rotary) gives a crude nitroalkane. Purification of the crude crude nitroalkane with vacuum distillation. Yields vary, approx 62 %. Oxidation of n-propylamine and higher alkane amines give nitroalkane at approx 62 %. [Note] Nitromethane and nitroethane form sodium water-soluable salts with 1M sodium hydroxide solution Refs: W.D. Emmons, Am.Soc. 79, 5528 (1957) Method 6: oxidation of ethyl amine with potassium permanganate Perhaps by the method in Org Synth CV 5, 845. REFS for methods 5 + 6: Chem.Ber. (1902) 35, 4294 Eur.J.Med.Chem. (1991) 26, 2, 167-178 Eur.J.Org.Chem. (1998) 4, 679-682 Heterocycles (1998) 48, 1, 181-185 J.Amer.Chem.Soc. (1954) 76, 4494 J.Amer.Chem.Soc. (1956) 78, 4003 J.Amer.Chem.Soc. (1957) 79, 5528 J.Chem.Soc.Chem.Commun. (1995) 15, 1523-1524 J.Org.Chem. (1960) 25, 2114-2126 J.Org.Chem. (1979) 44, 659-661. J.Org.Chem. (1992) 57, 25, 6759-6764 J.Org.Chem. (1993) 58, 5, 1118-1121 Magn.Reson.Chem. (1997) 35, 2, 131-140 Org.Synth. (1963) 43, 87 Tetrahedron (1991) 47, 28, 5173-5184 Tetrahedron (1995) 51, 41, 11305-11318 Tetrahedron Lett. (1981) 22, 18, 1655-1656 Tetrahedron Lett. (1986) 27, 21, 2335-2336 Tetrahedron Lett. (1996) 37, 6, 805-808 Z.Naturforsch.B (1989) 44, 11, 1475-1478 Method 7: destructive distillation of alpha-bromopropionic acid with sodium nitrite K2CO3 + NaNO2 + H2O + a-br-propionic acid à nitroethane 50%yield Add 20g of the acid to a solution of K2CO3 in the amount of base that causes the solution to be basic to phenolphthalein. The add 20g of NaNO2—there should be approx. 100ml of solution. Place in a 250ml rb flask and distill quickly- the first 100ml will come over before the rxn takes place. Then the nitroethane comes over. Distill until no more product comes over. (don’t distill to dryness) V. Auger. Bull. Soc. Chim. France Post no. 3, 23, 333 (1900) by the kolbe method. Method 8: oxidation of ethyl amine to nitroethane with dimethyldioxirane A new synthesis of nitro compounds using dimethyldioxirane(DMDO) Tetrahedron Letters,Vol.27,No.21,pp 2335-2336,1986 Abstract: Dimethyldioxirane oxidizes primary amines to nitro compounds in a facile, mild, high yield process. Here we report that aliphatic and aromatic primary amines are rapidly and efficiently oxidized to nitro compounds by dimethyldioxirane, DMDO. Indeed a survey of some general methods for the preparation of nitro compounds (2) suggests to us that the use of DMDO may be the method of choice. The conditions used are exceedingly mild and give the nitro compound as a solution in acetone. Table 1 summarizes our results with some representative amines. Table 1. Oxidation of amines with Dimethyldioxirane(DMDO). Amine Product Yield (Product m.p.(C) ~~~~~~~~~~~~~~~~~~~~~~~--~~~~~~--~---~~~~~~~~~~~-- Aniline Nitrobenzene 91 p-Anisidine p-Nitroanisole 94 54 n-Butylamine 1-Nitrobutane 84 sec-Butylamine 2-Nitrobutane 81 tert-Butylamine 2-Methyl-2-nitrobut 90 1-Aminoadamantane 1-Nitroadamsntane 95 159 Cyclohexylamine Nitrocyclohexane 95 trans-Azobenzene Axoxybenzene 96 36 In a typical reaction n-butylamine (0.052g; 0.7 mmol) in 5 ml of acetone was treated with 95 ml of DMDO, in acetone solution (ca 0.05M)(4) The solution was kept at room temperature for 30 min. with the exclusion of light. Analysis of the reaction mixture by capillary GC indicated the presence of l-nitrobutane only. The oxidations are believed to occur by means of successive oxidations by,1. In the aniline case the blue color of the nitroso conpound is observed immediately upon adding the solution of DMDO. In separate experiments we have shown that both phenylhydroxylamine and nitrosobenzene are readily oxidized to nitrobenzene by DMDO. The blue color of intermediate nitroso compound was observed in all of the amine oxidations. Dimethyldioxirane is a powerful oxygen atom donor, which oxidizes a variety of substrates 'including hydrocarbons'. Work is continuing on the oxidation of nitrogen-containing compounds by DMDO. 1. Chemistry of Dioxiranes. 5. Paper 4 of this series is J. Am. Chem. Soc., in press (1986). 2. H.O. Larson in The Chemistry of the Nitro and Nitroso Groups, H. Feuer, Ed., J. Wiley and Sons. N.Y. 1969. 4. The concentration of,DMDO in acetone was determined by titrating an aliquot with phenyl methyl sulfide. The synthesis of DMDO has been described (5). 5. R.W. Murray and R. Jeyaraman, J. Org. Chem., (50) 2847 (1985). Dioxiranes: synthesis and reactions of methyldioxiranes. J. Org. Chem. (1985), 50(16), 2847-53. Abstract The peroxymonosulfate-acetone system produces dimethyldioxirane under conditions permitting distn. of the dioxirane from the synthesis vessel. The same conditions were used to prep. other methyldioxiranes. Solns. of dimethyldioxirane prepd. in this manner were used to study its chem. and spectroscopic properties. The caroate-acetone system was also used to study the chem. of in situ generated dimethyldioxirane. cis- And trans-stilbenes were converted stereospecifically to the corresponding epoxides with dimethyldioxirane in acetone Other refs: Oxidation of primary amines by dimethyldioxirane: Murray, R.W.,S.N. Rajadhyaksha, L. Mohan, J. Org. Chem., 1989, 54, 5783 Method 9: isomerization of ethyl nitrite to nitroethane over asbestos catalyst J. Chem. Soc. 109, 701 (1916) (pass over asbestos in a tube furnace @ 120-130C for best results/best yield) Method 10: ethyl bromide, DMSO, NaNO2 and phloroglucinol dihydrate By Ritter, in Strike’s book- TSII. 32g or 26ml EtBr is poured into 250ml of DMSO with 36g NaNO2 and 52g phloroglucinol already present in solution. (Pglucinol is expensive but can be recycled) put on good mag. stirring and stopper the flask. Stir for two hours in emulsion form, then dump into a 600ml of ice water and extract twice with DCM. (2x200ml) dry the extracts with MgSO4 or CaCl2 the evap off the DCM. Distill and collect the fraction from 113-116C--- yields about 20g of nitroethane (80%) (another ref say maybe over 90% consistently) Other notes: catechol and resorcinol have the same nitrite scavenging abilities as phloroglucinol. And ethylene glycol can be used as a solvent. A simple NaOH wash of the final solution (nitroethane removed) will give the sodium salt of your phloroglucinol catalyst. Acidification of the solution will precip the catalyst for recovery by filtration. JACS 79, 2507 (1957) Tetrahedron vol 46, No 21, pp 7443-57 (1990) Ber. 11, 1332 (1878) Ber. 12, 417 (1879) JACS, Vol 78, 1497-1501 Method 11: 3-chloropropionic acid sodium salt, and NaNO2 ClCH2CH2COONa + NaNO2 à NO2CH2CH2COONa + NaCl NO2CH2CH2COONa + H2O –heatà NO2CH2CH3 + NaHCO3 From Organic Syntheses, Collective Vol. I, pp 401-403 To 500 g of chloroacetic acid in 500 g cracked ice add enough 40% NaOH solution to make the resulting mixture slightly alkaline. Do not let the temperature rise above 20 degrees C. This solution is mixed with 365 g sodium nitrite dissolved in 500 ml water in a 3 liter round-bottom flask. This flask should then be equipped with a thermometer dipping into the liquid and a distillation condenser. The mixture is carefully heated until the first bubbles or carbon dioxide appear (at about 80 C). The heat is then withdrawn and the heat of the reaction keeps it warm. If the reaction becomes too vigorous, it should be cooled. After the reaction ceases, heat cautiously until 110 C is reached. Nitromethane will distill over during this heating and the previous spontaneous heating. Separation of the nitromethane / water mixture and redistillation will give approx. 35 % yield after drying and redistillation Method 12: most complicated synth CH3CH=NOH + Cl2 à CH3CH (Cl)(NO) (ß gem-chloronitrosoethane) Gem-comp + O3 à CH3CH (Cl)(NO2) CH3CH (Cl)(NO2) + NaOH + H2 + Pd/C à nitroethane (50%) + HCl JOCS, Vol 41, pg 733-735 (1976) Method 13: electrochemical oxidation ---- not possible by method below Ethyl amine is oxidized to methyl nitrile in anhydrous solvent. In the presence of water it is oxidized to the imine, then acetaldehyde which is further oxidized to acetic acid. Method 14: Vapor Phase nitration of propane. The propane is bubbled through nitric acid heated to 108C and lead into a reactor at 420C. the product is then condensed and fractionated. (26% nitroethane formed) Industrial and Engineering Chemistry, Vol 28, Mar, 1936. Pg 339-344. JOC, Vol 17, pg 906-944. Method 15: Vapor Phase nitration of ethane. Same as propane but at least 80% yields. Industrial and Engineering Chemistry, Vol 28, Mar, 1936. Pg 339-344. JOC, Vol 17, pg 906-944. Method 16: Vapor Phase Nitration of Ethanol using Group II oxides or halides as a catalyst (works for methanol and propanol too) US pat # 4431842 Method 17: Distillation of alpha-bromopropionic acids with NaNO2 in the presence of Magnesium Sulfate in DMSO US pat # 4319059 (the alpha-bromo acid can be obtained using propionic acid in the procedure from Org. Synth. CV 1, 115.) This patent shows an easy route from alpha-bromopropionic acid to nitroethane in excellent yield. The patent also say that Magnesium chloride, bromide or sulfate may be used instead of the magnesium methoxide, but it doesn't say if this affects yields. The reaction proceeds as follows: In the polar aprotic solvent DMSO, the alpha-bromopropionic acid reacts in an SN2 fashion with nitrite ion to give alpha-nitropropionic acid and bromide ion. The role of the Mg2+ ion in the reaction is to facilitate the decarboxylation (removal of CO2) from the intermediate nitro acid, as it forms a chelate between one of the oxygen atoms on the nitro group and the oxygen anion of the carboxylic acid. The electron-withdrawing nature of the nitro group makes the carboxylic acid group labile, and it can easily be given off as carbon dioxide. If magnesium methoxide is used in place of the other magnesium salts, the carboxylic acid is directly deprotonated, probably making the reaction go even faster. There is no workup mentioned in the patent, but I'd suggest flooding with water (or using large amounts of dilute (5%) HCl in the hydrolysis step), and then extract the nitroethane with dichloromethane, ether or possibly petroleum ether. Then the combined organic layers are washed first with water and then with a concentrated NaCl solution, followed by drying the organic phase over anhydrous MgSO4, which is then filtered off. Then the solvent is removed distilled, and the residual crude nitroethane is fractionally distilled at 114-115°C. alpha-Bromopropionic acid can be made from propionic acid and phosphorous tribromide (from red phosphorous and bromine, the Hell-Volhard-Zelinsky reaction, http://www.geocities.com/chempen_software/reactions/RXN099.htm or http://www.orgsyn.org/orgsyn/default.asp?formgroup=base_form_group&dbname=orgsyn), or by HBr bromination of lactic acid (alpha-hydroxypropionic acid). Example 1 To a mixture of magnesium methoxide (0.11 mole) and dimethyl sulfoxide (50 ml) a-bromopropionic acid (0.11 mole) was added at 20°C. with stirring. To this mixture a solution of sodium nitrite (0.145 mole) in dimethyl sulfoxide (65 ml) was added at room temperature. Then, the reaction mixture was stirred at room temperature for 6 hours and was neutralized upon addition of diluted hydrochloric acid. Analysis of the reaction mixture indicated more than 99% conversion of alpha-bromopropionic acid and 94.5% yield of nitroethane. Example 2 In the manner of Example 1, sodium nitrite, alpha-bromopropionic acid and magnesium methoxide were reacted in dimethyl sulfoxide as the aprotic solvent. The reaction time was 2 hours for one run and 22 hours for another. Reaction was conducted at room temperature. The run at 2 hours converted only 94.5% of the acid and yielded 72.7% nitroethane. The second run at 22 hours gave a conversion of > 99% and a yield of 100%. At room temperature the reaction apparently takes about 4-5 hours to go to completion. At higher temperatures of 40°C. up to about 75°C. the reaction time is shorter. Thus, one or two hours or even less time at 75°C. will completely convert the bromoacid to the intermediate which can then be decomposed to the nitroalkane. When using dimethyl sulfoxide as solvent temperatures approaching 100°C should be avoided since the solvent will volatilize and decompose at about 100°C. Other aprotic solvents may not have this disadvantage Method 18: Oxidation of alanine with permanganate followed by decarboxylation Nitroethane via oxidation of alanine? Theory ------ MeCH(NH2).COOH + 3(O) --> MeCH(NO2).COOH + H2O. MeCH(NO2).COOH + NaOH --> MeCH(NO2).COONa. MeCH(NO2).COONa + H2O --> MeCH2(NO2) + NaHCO3. Procedure --------- A solution of potassium permanganate (0.3 mol) in water was made by dissolving 47.41 g KMnO4 in 400 mL hot water in a 1 L 3-necked flask fitted with a reflux condenser, a stirbar[note 1], thermometer, and a 100-mL addition funnel. As the solution cools to room temperature fine crystals of KMnO4 crystallise out of solution[note 2]. A solution of alanine (0.1 mol, 8.91 g) in 65 mL of water was placed in the addition funnel and added dropwise with stirring over a 20 minute period. The temperature slowly rose. When the addition was complete, the reaction mixture was heated to 60º over a period of approximately 2 hours. 40 mL of acetone was added [note 3] and then the reaction mixture maintained at 70-85º [the sludge was extremely viscous and the stirbar was of no use] for 2 hours. 0.1 mol sodium hydroxide in 20 mL of water was then added through the addition funnel. Pause (to be completed). ----- The flask showed no sign of heating up after addition of the NaOH. By now the black/brown sludge will not mix (with the stir-bar). The next step is to heat to 80-100C to decarboxylate any nitro-propionic acid and then to steam distil. Notes: ------ 1. An overhead stirrer is essential - the stirbar will get clogged with MnO2. 2. KMnO4 solubility is 1 in 3.5 parts of hot water and 1 in 14 parts of cold water. 3. The acetone was added to try to clear the sludge. I would have added more but I had second thoughts. Refs: 1. Synthesis Of Aliphatic And Alicyclic Nitro Compounds; Org. Syn. p 131-132 [The Oxidation of Amines] 2. Organic Syntheses, Vol. 52, pp 77-82, 2-Metryl-2-Nitrosopropane and its Dimer, A. Calder, A. R. Forrester and S. P. Hepburn. 3. Vogel's Practical Organic Chemistry, 4th ed. P 564 'Nitromethane'. Questions. ---------- 1. Is it safe to heat this mixture to 90C without a stirrer? [the next step to make sure that nitro-propionic acid is decarboxylated] 2. Should I improvise an overhead stirrer to finish this off? 3. Nitroethane will steam distil won't it? 4. Should the permanganate have been buffered? 5. I think the NaOH should have been in there from the start. The sodium salt of alanine would have been a better idea? 6a. Would the reaction benefit from taking place in an organic solvent? 6b. If so, what solvents are suitable apart from acetone? I will repeat this - with an overhead stirrer and the addition of sodium salt of alanine rather than alanine followed by NaOH. Method 19: Reduction of acetaldehyde oxime and oxidation of the product Good work ! An alternative method to alanine amino oxidation and decarboxylation is the reaction : CH3CHO + NH2OH ==>> CH3CH=NOH, Then carfully reduced to CH3CH2NHOH, and then oxidized as proposed by you above to get CH3CH2NO nitroethane from acetaldoxime J.H. Boyer / H. Alul, Am.Soc. 81, 4237 (1959) Method 20: Oxidation of ethyl amine with CrO3 Somewhere in Vogel’s (the oxidation) Method 21: Nitroethane from propyl nitrate J.B. Levy / F.J. Adrian, Am.Soc. 77, 2015 (1954) Method 22: Nitroethane from nitroethene (and nitroethanol) Nitromethane and formaldehyde will produce nitroethene in vapor phase, over silica-supported lead catalysts at 200o. You can always use Baker's yeast. Nitroalkene in Pet. Ether with bakers yeast for a couple days will reduce it to the nitroalkane. CH3NO2 + HCOH == NaOH ==>> HOCH2CH2NO2 Aldol Condensation. HOCH2CH2NO2 == heat ==>> H2C=CH-NO2 + H2O nitromethane and formaldehyde are reacted in alkaline solution, they give nitroethanol; this can bee dehydrated to nitroethene by concentrated acid, or again in vapor phase, passing over phosphoric acid or boric anhydride. Suppose one wanted to use such means to convert nitromethane, which is easy to get, to nitroethane, which is not. A selective reduction of the double bond, in the presence of the nitro group, would do the trick As an alternative: in general, aldehydes and ketones will also react in the presence of alumina and KF ( at r.t.) to form beta-nitroalcohols, which typically dehydrate to nitroalkenes in very acidic conditions. See Tetrahedron Letters, Vol 27, 1986, p493. This article doesn't specifically use nitroethene as an example, but the other compounds tested (which are larger) gave yields of nitroalcohol around 70%. The conversion to the nitroalkene should be stoichiometric. I expect this method may also yield nitrostyrenes with a similar degree of success



Antoncho (Official Hive Translator) 11-19-01 03:15 No 238348	Re: What can be done to improve the performance of clandestine nitroethane synth?	Bookmark Reply
	i think Megamole has an interesting article on peracetic acid oxid'n of alkylamines... Anyone wishes to ask him for it? Antoncho



Aurelius (Hive Bee) 09-11-02 13:09 No 355380	newest method (Rated as: excellent)	Bookmark Reply
	here's what available on the hive, thus far: Nitroethane synthesis: a compilation Method 1: from sodium ethyl sulfate and a metal nitrite 1.5 mole sodium nitrite (103.5g) is intimately mixed with 1 mole of sodium ethyl sulfate (158g) and 0.0625 moles of K2CO3 (8.6g). The mixture is then heated to 125-130°C, at which temperature the nitroethane distills over as soon as it is formed. The heating is discontinued when the distillation flow slackens considerably, and the crude nitroethane is washed with an equal amount of water, dried over CaCl2, and if needed, decolorized with a little activated carbon. The nitroethane is then re-distilled, collecting the fraction between 114-116°C. Yield 46% of theory (another ref says max. 42%) Chemical Abstracts, Vol 49, pg 836. Method 2: from diethyl sulfate and sodium nitrite Initial run - Into a stoppered bottle was placed a mixture of diethyl sulfate (120g) and sodium nitrite solution (120g in 160ml of water.) The bottle was shaken mechanically for 20 hours, the pressure being released at intervals. The contents were then poured into a separating funnel, and the upper layer separated, dried over calcium chloride. and distilled at 14 mmHg, the distillate up to 60°C being collected (the residue, ca. 230g., consisted of ethyl sulphate and was used again). The distillate was fractionated at atmospheric pressure, and the fraction of bp 114-116°C collected. This was shaken with water, dried over calcium chloride, run through charcoal, and redistilled; bp 114-115.5°C. Yield, 17.7g. (31%, or allowing for recovered ethyl sulfate, 43.5%). Routine run - A second experiment was then carried out using the same quantity of ethyl sulfate as above. The recovered nitrite solution (lower layer) from the first run was concentrated by adding approximately 16 g. of sodium nitrite per 160ml of solution. Yield 26.4g (46%, or allowing for recovered ethyl sulphate, 65%). For each additional subsequent run approximately 16 g. of nitrite per 160 ml of solution were added, although this represents a rather diminishing concentration in view of the increased yield of nitroethane Method 3: from ethyl bromide (iodide) and sodium nitrite (dmf) 32.5 grams of ethyl bromide (0.3 moles) was poured into a stirred solution of 600ml dimethylformamide and 36 grams dry NaNO2 (0.52 mole) in a beaker standing in a water bath keeping the solution at room temperature as the reaction is slightly exothermic. Always keep the solution out of direct sunlight. The stirring was continued for six hours. After that, the reaction mixture was poured into a 2500 ml beaker or flask, containing 1500 ml ice-water and 100 ml of petroleum ether. The petroleum ether layer was poured off and saved, and the aqueous phase was extracted four more times with 100 ml of petroleum ether each, where after the organic extracts were pooled, and in turn was washed with 4x75ml of water. The remaining organic phase was dried over magnesium sulfate, filtered, and the petroleum ether was removed by distillation under reduced pressure on a water bath, which temperature was allowed to slowly rise to about 65°C. The residue, consisting of crude nitroethane was distilled under ordinary pressure (preferably with a small distillation column) to give 60% of product, boiling at 114-116°C. The ethyl bromide reacts with NaNO2, forming nitroethane and ethyl nitrite. This method can be varied in a few ways. Firstly, dimethyl sulfoxide (DMSO) can be substituted for the dimethylformamide (DMF) as solvent. Ethylene glycol also works as solvent, but the reaction proceeds pretty sluggishly in this medium, allowing for side reactions, such as this: RH-NO2 + R-ONO => R-(NO)NO2 + R-OH. KNO2 can also be used instead of NaNO2. If NaNO2 is used in DMF, 30g (0.5 mol) of urea can also be added as nitrite scavenger to minimize side reactions, as well as simultaneously increasing the solubility of the NaNO2 and thereby significantly speeding up the reaction. If the ethyl bromide is substituted with ethyl iodide, the required reaction time is decreased to only 2.5 h instead of 6 h. In case ethyl iodide is employed, a slight change in the above procedure needs to be done. The pooled pet ether extracts should be washed with 2x75ml 10% sodium thiosulfate, followed by 2x75ml water, instead of 4x75ml water as above. This to remove small amounts of free iodine Method 4 : from ethyl halide and silver nitrite Cool 100 g of silver nitrite (0.65 mol) in 150 ml of dry ether to 0°C in a 3 neck 500 ml flask (in a darkened room or using yellow light). Add 0.5 moles of ethyl halide (78g ethyl iodide or 55g of ethyl bromide) dropwise over a 2 hour period while stirring constantly and maintaining the temperature at 0°C and dark conditions. Stir for 24 hours at 0°C, then 24 hours at room temp if using ethyl bromide, and 48h if using ethyl bromide. (Test for halogens to see when the reaction is completed, through adding a few drops of the reaction mixture to a test tube containing an alcoholic solution of silver nitrate and note if a precipitate appears. If so, the reaction is not complete. The Beilstein test can also be used, it uses a small coil of copper wire in a test tube to which a small portion of the reaction mixture is added and it is noted if reaction occurs, where elemental silver will deposit on the surface of the copper coil.) Silver iodide (or bromide) will precipitate in the solution during the course of the reaction. Filter off the silver salt, and wash it with several portions of ether. Evaporate the ether at room temperature. (This may be substituted with distillation of the ether using a water bath at atmospheric pressure. A 2x45 cm column packed with 4 mm pyrex helices is used. A more efficient column is not used due to the instability of the ethyl nitrite formed as a by-product in the reaction. Maintain anhydrous conditions since the ethyl nitrite will hydrolyze to ethanol and will be difficult to separate.) Then vacuum distill the residue at about 5 mmHg. The ethyl nitrite will be the initial fraction, followed by an intermediate fraction, then the nitroethane will distill. The yield is about 83% of theory Method 5: oxidation of ethyl amine with peracids (m-perbenzoicacid) General Procedure for the Oxidation of Primary & Secondary amines using m-chloroperbenzoic acid. m-Chloroperbenzoic acid (4.1g, 0.02mol, 85% pure) is dissloved in 30 mls of 1,2-dichloroethane in a three-neck flask equipped with a condenser and a pressure-equalising dropping funnel. The amine (0.005 mol) in 3-5 mls of 1,2-dichloroethane solvent is added drop-wize to the refluxing m-Chloroperbenzoic acid/1,2-dichloroethane solution. Refluxing temperature 83oC for 3 hours. After the addition of the amine and refluxing time, the reaction mixture is cooled, filtered and washed with three 50 ml portions of 1M sodium hydroxide solution and dried over anhydrous magnesium sulphate. The removal of the 1,2-dichloroethane solvent by distillation (rotary) gives a crude nitroalkane. Purification of the crude crude nitroalkane with vacuum distillation. Yields vary, approx 62 %. Oxidation of n-propylamine and higher alkane amines give nitroalkane at approx 62 %. [Note] Nitromethane and nitroethane form sodium water-soluable salts with 1M sodium hydroxide solution Method 6: oxidation of ethyl amine with potassium permanganate Perhaps by the method in Org Synth CV 5, 845. REFS for methods 5 + 6: Chem.Ber. (1902) 35, 4294 Eur.J.Med.Chem. (1991) 26, 2, 167-178 Eur.J.Org.Chem. (1998) 4, 679-682 Heterocycles (1998) 48, 1, 181-185 J.Amer.Chem.Soc. (1954) 76, 4494 J.Amer.Chem.Soc. (1956) 78, 4003 J.Amer.Chem.Soc. (1957) 79, 5528 J.Chem.Soc.Chem.Commun. (1995) 15, 1523-1524 J.Org.Chem. (1960) 25, 2114-2126 J.Org.Chem. (1979) 44, 659-661. J.Org.Chem. (1992) 57, 25, 6759-6764 J.Org.Chem. (1993) 58, 5, 1118-1121 Magn.Reson.Chem. (1997) 35, 2, 131-140 Org.Synth. (1963) 43, 87 Tetrahedron (1991) 47, 28, 5173-5184 Tetrahedron (1995) 51, 41, 11305-11318 Tetrahedron Lett. (1981) 22, 18, 1655-1656 Tetrahedron Lett. (1986) 27, 21, 2335-2336 Tetrahedron Lett. (1996) 37, 6, 805-808 Z.Naturforsch.B (1989) 44, 11, 1475-1478 Method 7: destructive distillation of alpha-bromopropionic acid with sodium nitrite K2CO3 + NaNO2 + H2O + a-br-propionic acid à nitroethane 50%yield Add 20g of the acid to a solution of K2CO3 in the amount of base that causes the solution to be basic to phenolphthalein. The add 20g of NaNO2—there should be approx. 100ml of solution. Place in a 250ml rb flask and distill quickly- the first 100ml will come over before the rxn takes place. Then the nitroethane comes over. Distill until no more product comes over. (don’t distill to dryness) V. Auger. Bull. Soc. Chim. France Post no. 3, 23, 333 (1900) by the kolbe method. Method 8: oxidation of ethyl amine to nitroethane with dimethyldioxirane A new synthesis of nitro compounds using dimethyldioxirane(DMDO) Tetrahedron Letters,Vol.27,No.21,pp 2335-2336,1986 Abstract: Dimethyldioxirane oxidizes primary amines to nitro compounds in a facile, mild, high yield process. Here we report that aliphatic and aromatic primary amines are rapidly and efficiently oxidized to nitro compounds by dimethyldioxirane, DMDO. Indeed a survey of some general methods for the preparation of nitro compounds (2) suggests to us that the use of DMDO may be the method of choice. The conditions used are exceedingly mild and give the nitro compound as a solution in acetone. Table 1 summarizes our results with some representative amines. Table 1. Oxidation of amines with Dimethyldioxirane(DMDO). Amine Product Yield (Product m.p.(C) ~~~~~~~~~~~~~~~~~~~~~~~--~~~~~~--~---~~~~~~~~~~~-- Aniline Nitrobenzene 91 p-Anisidine p-Nitroanisole 94 54 n-Butylamine 1-Nitrobutane 84 sec-Butylamine 2-Nitrobutane 81 tert-Butylamine 2-Methyl-2-nitrobut 90 1-Aminoadamantane 1-Nitroadamsntane 95 159 Cyclohexylamine Nitrocyclohexane 95 trans-Azobenzene Axoxybenzene 96 36 In a typical reaction n-butylamine (0.052g; 0.7 mmol) in 5 ml of acetone was treated with 95 ml of DMDO, in acetone solution (ca 0.05M)(4) The solution was kept at room temperature for 30 min. with the exclusion of light. Analysis of the reaction mixture by capillary GC indicated the presence of l-nitrobutane only. The oxidations are believed to occur by means of successive oxidations by,1. In the aniline case the blue color of the nitroso conpound is observed immediately upon adding the solution of DMDO. In separate experiments we have shown that both phenylhydroxylamine and nitrosobenzene are readily oxidized to nitrobenzene by DMDO. The blue color of intermediate nitroso compound was observed in all of the amine oxidations. Dimethyldioxirane is a powerful oxygen atom donor, which oxidizes a variety of substrates 'including hydrocarbons'. Work is continuing on the oxidation of nitrogen-containing compounds by DMDO. 1. Chemistry of Dioxiranes. 5. Paper 4 of this series is J. Am. Chem. Soc., in press (1986). 2. H.O. Larson in The Chemistry of the Nitro and Nitroso Groups, H. Feuer, Ed., J. Wiley and Sons. N.Y. 1969. 4. The concentration of,DMDO in acetone was determined by titrating an aliquot with phenyl methyl sulfide. The synthesis of DMDO has been described (5). 5. R.W. Murray and R. Jeyaraman, J. Org. Chem., (50) 2847 (1985). Dioxiranes: synthesis and reactions of methyldioxiranes. J. Org. Chem. (1985), 50(16), 2847-53. Abstract The peroxymonosulfate-acetone system produces dimethyldioxirane under conditions permitting distn. of the dioxirane from the synthesis vessel. The same conditions were used to prep. other methyldioxiranes. Solns. of dimethyldioxirane prepd. in this manner were used to study its chem. and spectroscopic properties. The caroate-acetone system was also used to study the chem. of in situ generated dimethyldioxirane. cis- And trans-stilbenes were converted stereospecifically to the corresponding epoxides with dimethyldioxirane in acetone Method 9: isomerization of ethyl nitrite to nitroethane over asbestos catalyst J. Chem. Soc. 109, 701 (1916) (pass over asbestos in a tube furnace @ 120-130C for best results/best yield) Method 10: ethyl bromide, DMSO, NaNO2 and phloroglucinol dihydrate By Ritter, in Strike’s book- TSII. 32g or 26ml EtBr is poured into 250ml of DMSO with 36g NaNO2 and 52g phloroglucinol already present in solution. (Pglucinol is expensive but can be recycled) put on good mag. stirring and stopper the flask. Stir for two hours in emulsion form, then dump into a 600ml of ice water and extract twice with DCM. (2x200ml) dry the extracts with MgSO4 or CaCl2 the evap off the DCM. Distill and collect the fraction from 113-116C--- yields about 20g of nitroethane (80%) (another ref say maybe over 90% consistently) Other notes: catechol and resorcinol have the same nitrite scavenging abilities as phloroglucinol. And ethylene glycol can be used as a solvent. A simple NaOH wash of the final solution (nitroethane removed) will give the sodium salt of your phloroglucinol catalyst. Acidification of the solution will precip the catalyst for recovery by filtration. JACS 79, 2507 (1957) Tetrahedron vol 46, No 21, pp 7443-57 (1990) Ber. 11, 1332 (1878) Ber. 12, 417 (1879) JACS, Vol 78, 1497-1501 Method 11: 3-chloropropionic acid sodium salt, and NaNO2 ClCH2CH2COONa + NaNO2 à NO2CH2CH2COONa + NaCl NO2CH2CH2COONa + H2O –heatà NO2CH2CH3 + NaHCO3 Modification of Nitromethane synthesis from Organic Synthesis, Vol? Pg 401. Method 12: most complicated synth CH3CH=NOH + Cl2 à CH3CH (Cl)(NO) (ß gem-chloronitrosoethane) Gem-comp + O3 à CH3CH (Cl)(NO2) CH3CH (Cl)(NO2) + NaOH + H2 + Pd/C à nitroethane (50%) + HCl JOCS, Vol 41, pg 733-735 (1976) Method 13: electrochemical oxidation ---- not possible by method below Ethyl amine is oxidized to methyl nitrile in anhydrous solvent. In the presence of water it is oxidized to the imine, then acetaldehyde which is further oxidized to acetic acid. Method 14: Vapor Phase nitration of propane. The propane is bubbled through nitric acid heated to 108C and lead into a reactor at 420C. the product is then condensed and fractionated. (26% nitroethane formed) Industrial and Engineering Chemistry, Vol 28, Mar, 1936. Pg 339-344. JOC, Vol 17, pg 906-944. Method 15: Vapor Phase nitration of ethane. Same as propane but at least 80% yields. Industrial and Engineering Chemistry, Vol 28, Mar, 1936. Pg 339-344. JOC, Vol 17, pg 906-944. Method 16: Vapor Phase Nitration of Ethanol using Group II oxides or halides as a catalyst (works for methanol and propanol too) US pat # 4431842 Method 17: Distillation of alpha-bromopropionic acids with NaNO2 in the presence of Magnesium Sulfate in DMSO US pat # 4319059 (the alpha-bromo acid can be obtained using propionic acid in the procedure from Org. Synth. CV 1, 115.) Method 18: Oxidation of alanine with permanganate followed by decarboxylation Nitroethane via oxidation of alanine? Theory ------ MeCH(NH2).COOH + 3(O) --> MeCH(NO2).COOH + H2O. MeCH(NO2).COOH + NaOH --> MeCH(NO2).COONa. MeCH(NO2).COONa + H2O --> MeCH2(NO2) + NaHCO3. Procedure --------- A solution of potassium permanganate (0.3 mol) in water was made by dissolving 47.41 g KMnO4 in 400 mL hot water in a 1 L 3-necked flask fitted with a reflux condenser, a stirbar[note 1], thermometer, and a 100-mL addition funnel. As the solution cools to room temperature fine crystals of KMnO4 crystallise out of solution[note 2]. A solution of alanine (0.1 mol, 8.91 g) in 65 mL of water was placed in the addition funnel and added dropwise with stirring over a 20 minute period. The temperature slowly rose. When the addition was complete, the reaction mixture was heated to 60º over a period of approximately 2 hours. 40 mL of acetone was added [note 3] and then the reaction mixture maintained at 70-85º [the sludge was extremely viscous and the stirbar was of no use] for 2 hours. 0.1 mol sodium hydroxide in 20 mL of water was then added through the addition funnel. Pause (to be completed). ----- The flask showed no sign of heating up after addition of the NaOH. By now the black/brown sludge will not mix (with the stir-bar). The next step is to heat to 80-100C to decarboxylate any nitro-propionic acid and then to steam distil. Notes: ------ 1. An overhead stirrer is essential - the stirbar will get clogged with MnO2. 2. KMnO4 solubility is 1 in 3.5 parts of hot water and 1 in 14 parts of cold water. 3. The acetone was added to try to clear the sludge. I would have added more but I had second thoughts. Refs: 1. Synthesis Of Aliphatic And Alicyclic Nitro Compounds; Org. Syn. p 131-132 [The Oxidation of Amines] 2. Organic Syntheses, Vol. 52, pp 77-82, 2-Metryl-2-Nitrosopropane and its Dimer, A. Calder, A. R. Forrester and S. P. Hepburn. 3. Vogel's Practical Organic Chemistry, 4th ed. P 564 'Nitromethane'. Questions. ---------- 1. Is it safe to heat this mixture to 90C without a stirrer? [the next step to make sure that nitro-propionic acid is decarboxylated] 2. Should I improvise an overhead stirrer to finish this off? 3. Nitroethane will steam distil won't it? 4. Should the permanganate have been buffered? 5. I think the NaOH should have been in there from the start. The sodium salt of alanine would have been a better idea? 6a. Would the reaction benefit from taking place in an organic solvent? 6b. If so, what solvents are suitable apart from acetone? I will repeat this - with an overhead stirrer and the addition of sodium salt of alanine rather than alanine followed by NaOH. Method 19: Reduction of acetaldehyde oxime and oxidation of the product Good work ! An alternative method to alanine amino oxidation and decarboxylation is the reaction : CH3CHO + NH2OH ==>> CH3CH=NOH, Then carfully reduced to CH3CH2NHOH, and then oxidized as proposed by you above to get CH3CH2NO NEWEST METHOD--- Method 20: reduction of nitroethene to nitroethane using 2-phenylbenzimidazoline http://www.rhodium.ws/chemistry/phenylbenzimidazoline.html just thought aurelius would add it to the compilation for posterity and preservation



Bwiti (PVC-Analog Taste-Tester) 09-11-02 20:00 No 355492	"A post showed up a few months ago here on the ...	Bookmark Reply
	"A post showed up a few months ago here on the boards describing the failure of NaNO2 and ethyl bromide in a polar aprotic solvent (DMF,DMSO and n-Methylpyrolidinone) to form nitroethane." A complete failure? Come on, please tell me you're joking! Love my country, fear my government.



SpicyBrown (Hive Bee) 09-12-02 01:20 No 355571	Was a nitrite scavenger present?	Bookmark Reply
	"A post showed up a few months ago here on the boards describing the failure of NaNO2 and ethyl bromide in a polar aprotic solvent (DMF,DMSO and n-Methylpyrolidinone) to form nitroethane." A complete failure? Come on, please tell me you're joking! SWIM wonders, was a catechol-type nitrite scavenger used? Quite some time ago, a FOAF or what-not had a failure with EtBr/NaNO2 in DMSO, but not only was the DMSO shit-grade, no nitrite scavenger was used. The FOAF indicates soon the dream will be thought about again in either n,n-DMF or redistilled DMSO with catechol present. Any idea if propylene glycol will work as a solvent? SpicyBrown



Bwiti (PVC-Analog Taste-Tester) 09-12-02 18:51 No 355767	I assumed that since it was on Rhodium's page, ...	Bookmark Reply
	I assumed that since it was on Rhodium's page, then it would work without phlorogluc-whatever - Can't find a source for it that I'm comfortable buying from. I just can't see how one person can fail, then another can get a 60% yield? Is someone full of shit, or did someone fail because they accidentally urinated in the rxn while they were drunk? I don't think that the use of DMSO in place of dimethylformamide would be a problem, but I'm not a chemist. Fuck it, when I get the chems, I'll try it out and post it. What else do I have to lose besides throwing money out the window. Love my country, fear my government.

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