Author Topic: What can be done to improve the performance of clandestine nitroethane synth?  (Read 10982 times)

0 Members and 1 Guest are viewing this topic.

rev drone

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
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 1879 (not existing)). 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

  • Guest
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

  • Guest
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.

Ritter

  • Guest
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

  • Guest
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!

ymir

  • Guest
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

  • Guest
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

  • Guest
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

  • Guest
This sounds like an interesting thread. I ESPECIALLY would like someone to fetch the reference mentioned in

Post 103085

(Alchemy: "Re: What can be done to improve the performance of clandestine nitroethane synth?", Chemistry Discourse)
.

Aurelius

  • Guest
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 ? 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 @ 120-130*C 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 113-116*C--- 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 ? NO2CH2CH2COONa + NaCl

   NO2CH2CH2COONa + H2O –heat?  NO2CH2CH3 + NaHCO3

Modification of Nitromethane synthesis from Organic Synthesis, Vol? Pg 401.

Method 12:  most complicated synth

   CH3CH=NOH  + Cl2 ? CH3CH (Cl)(NO)   (? gem-chloronitrosoethane)

   Gem-comp + O3 ? CH3CH (Cl)(NO2)

   CH3CH (Cl)(NO2) + NaOH + H2 + Pd/C ? 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 108*C and lead into a reactor at 420*C.  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