Author Topic: What can be done to improve the performance of clandestine nitroethane synth?  (Read 60472 times)

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sponsan

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I shouldn't have used the word "OTC" - sorry my ...
« Reply #40 on: November 12, 2002, 02:03:00 AM »
I shouldn't have used the word "OTC" - sorry my mistake.  What i should have said is "The product was found to be available outside of chemical supply houses".

scram

  • Guest
Someone else mentioned a nitro-ethane reduction ...
« Reply #41 on: November 14, 2002, 09:17:00 PM »
Someone else mentioned a nitro-ethane reduction insitu of nitro-methane here once. I still have my doubts  that guy actually got the shit from his otc drag strip. I live near a major city and I scoured every hobby shop and drag race strip with the area and NONE even had nitromethane. Thanks to Bin Laden, the FBI was even asking local shops about anyone buying model rocket engines after that. Dont ask?! The only place I was able to find ethane was through industrial supply that have chem companies behind them with huge 3 letter names. I wasn't about to venture even trying to build an account with even their smaller distributer and pop off a liter of nitroethane as one of their "free samples." Sponsan if you can pm me and clue me in on how your pulling this off I can do some tricks for you too.

Aurelius

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Rhodium
« Reply #42 on: November 22, 2002, 11:47:00 AM »
Hey Rhodium, just noticed that your page (and apparently this thread) lacks mention of US4319059.  please include it on the FAQ at your site.  thanks (if you need aurelius to type out the patent, yet aurelius know)


Rhodium

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US Patent 4,319,059
« Reply #43 on: November 22, 2002, 01:44:00 PM »
I have it on my hard drive, but I didn't think it was useful to upload it there before I had collected a few methods on making 2-bromopropionic acid to go with it... I'm too much of a perfectionist.

SUMMARY OF THE INVENTION

An .alpha.-bromoalkanoic acid, e.g., .alpha.-bromopropionic acid, is reacted with an alkali metal nitrite, e.g., NaNO2 in the presence of Mg2+ ion provided by adding a magnesium salt, e.g., MgSO4, to the mixture, all in a solution of an aprotic solvent, e.g., dimethyl sulfoxide. This mixture is allowed to react with stirring at room temperature and then neutralized with a mineral acid, e.g., HCl. The product is a nitroalkane, which in the case of starting with .alpha.-bromopropionic acid is nitroethane.

DETAILED DESCRIPTION OF THE INVENTION

Without attempting to describe the mechanism, the following equation shows the reaction: ##STR1## wherein M is an alkali metal R is H or an alkyl group of 1-4 carbon atoms and the solvent is aprotic. After reacting the mixture it is neutralized with a mineral acid.

Thus, an .alpha.-bromoalkanoic acid reacted with an alkali metal nitrite in the presence of Mg.sup.++ ion in an aprotic solvent will yield a nitroalkane having one less carbon atom than the starting bromo-alkanoic acid. The alkali metal is converted to the salt of the mineral acid used to neutralize the mixture.

The .alpha.-bromo acids useful in the process are, for, example bromoalkanoic acids having from 2 to 6 carbon atoms. Thus, .alpha.-bromoacetic, .alpha.-bromopropionic, .alpha.-bromobutanoic, .alpha.bromopentanoic and the like acids maybe employed.

Alkali metal nitrites useful in the process are sodium and potassium nitrites. It is believed that the function of the magnesium ion is to form a chelate intermediate which can then be decomposed by the addition of a mineral acid, decarboxylating the alkanoic acid moiety. Ionizable magnesium compounds useful in the process are magnesium alkoxides, such as magnesium methoxide, magnesium sulfate, magnesium chloride or bromide.

Both the magnesium compound and the nitrite are employed in a molar equivalent amount based on the moles of bromo acid used. In order to insure complete reaction of the halo acid a slight excess of each of these is employed. The reaction to form the chelate is considered complete upon the substantial disappearance of the nitrite, i.e., the amount equivalent to the bromoacid.

Aprotic solvents employed are selected from amides and sulfoxides, e.g., dimethyl formamide and dimethyl sulfoxide.

EXAMPLE 1

To a mixture of magnesium methoxide (0.11 mole) and dimethyl sulfoxide (50 ml) .alpha.-bromopropionic acid (0.11 mole) ws 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.degree. C. should be avoided since the solvent will volatilize and decompose at about 100.degree. C. Other aprotic solvents may not have this disadvantage.

RedMonn_16

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Overseas suppliers.
« Reply #44 on: November 28, 2002, 01:23:00 PM »

roger2003

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Method 2: from diethyl sulfate and sodium nitrite ...
« Reply #45 on: November 30, 2002, 08:47:00 AM »
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



The bottle was "shaken mechanically" for 20 hours

Does this procedure also run, if the mixture is stirring in a stainlees steel vessel in larger amounts?


roger2003

Rhodium

  • Guest
Yes, it will run even if stirred, and not shaken.
« Reply #46 on: November 30, 2002, 10:14:00 AM »
Yes, it will run even if stirred, and not shaken. Just make sure you have vigorous stirring, and it won't be much different. I don't have the original article handy right now, but I think I remember the authors saying that the reaction could get out of hand if scaled up too much, pay attention to the second sentence about pressure building up! It might be necessary to run the reaction in a closed system though, I have a hunch that maybe the reaction will produce more ethyl nitrite gas and less nitroethane if run open to the atmosphere. Increased pressure favors the formation of nitroethane.

lugh

  • Guest
Phlorglucinol synthesis details
« Reply #47 on: December 04, 2002, 03:20:00 AM »
From Perkin:

Phlorglucinol is best prepared by fusing one part resorcinol with six parts sodium hydroxide for about twenty five minutes, or until the vigorous evolution of hydrogen has ceased; the chocolate colored melt is dissolved in water, acidified with sulfuric acid, extracted with ether, the ethereal extract evaporated, and the residue recrystallized from water  :)

senzualus

  • Guest
NO3 -> NO2 ?
« Reply #48 on: December 24, 2002, 09:49:00 PM »
I've just got my hands on some benzaldehyde and since I can't get or make Et-NO2(can't find anywhere DMF or DMSO or any of the reactives in the posts)things are getting a bit frustrating..so please give some sugestions:

-I belive that by nitration of ethanol (with HNO3 & H2SO4 analog nitroglycerine nitration)one should get Et-ONO2. Right?

-is it posible to reduce the -ONO2 group to -NO2 using the stoichiometric amount of reduced iron or hydrazine/HO[/sup]- to get nitroethane?

-there must be a way to get speed somewhat OTC other than the cinnamic acid route?


Polverone

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careful
« Reply #49 on: December 24, 2002, 11:41:00 PM »
If my recollection of The Chemistry of Powder and Explosives is correct, ethanol can be nitrated only by using pure, nitrous acid-free nitric acid. Nitrous acid contamination or the use of mixed acid may both lead to explosive reactions. But that doesn't really matter, because I'm pretty sure that reduction of ethyl nitrate will lead to ethyl nitrite, not nitroethane. The oxygen that you want to remove is stuck between the nitrogen atom and a carbon, but you're going to end up removing one of the oxygens that's just dangling off of the nitrogen.

19th century digital boy

Rhodium

  • Guest
Nitroethane from ethanol
« Reply #50 on: December 26, 2002, 01:51:00 AM »
Treatment of ethanol with nitric acid will give ethyl nitrate (EtONO2), but this is a sensitive explosive similar to nitroglycerin, so please don't do that. Treatment of ethanol with NaNO2 and H2SO4 will give ethyl nitrite (EtONO)1 with then in turn can be isomerized to nitroethane (EtNO2)2.

1:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/eleusis/nitrites20.html


2:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitrite2nitro.html


Aurelius

  • Guest
Ethyl nitrite to Nitroethane
« Reply #51 on: December 26, 2002, 06:46:00 PM »
aurelius prefers this instead- much more efficient and less hassle than setting up a industrial reactor (furnace) and safer too (in aurelius' opinion, at least for newbees)

US Patent 4,319,059

Post 382212

(Rhodium: "US Patent  4,319,059", Chemistry Discourse)


senzualus

  • Guest
heterogenous reaction? (sorry 'bout the spelling)
« Reply #52 on: December 28, 2002, 03:15:00 PM »
What if someone would put in an Erlenmeyer flask some halogenated alkane (like Et-Cl or Et-Br) and then add an xs of NaNO2 and just let it sit there for a couple of days?

I think the reaction time would be somewhat long but probably some kind of (acid?) catalist may be used -like ZnCl2? or a little HCl or HBr?- to accelerate the transformation.

I don't know about any secondary reactions that may occur but I think the general idea is pretty good  :P  and may be worth trying.

I experimented once but by some reason (at that time I did not need any nitroethane) I flushed it down the toilet  ;D  !
Unfortunately,  now I'm waitin' to go to school since I don't have any NaNO2 left  ;) ...

If anyone tries this please post the results :) .

Rhodium

  • Guest
Result of Ethyl Halide & NaNO2
« Reply #53 on: December 29, 2002, 05:30:00 AM »
You would end up with a combination of "it didn't work" and "ethyl nitrite was formed"...

El_Zorro

  • Guest
So what about this? http://www.rhodium.ws/chemi...
« Reply #54 on: December 29, 2002, 05:53:00 AM »
So what about this?

https://www.thevespiary.org/rhodium/Rhodium/chemistry/alcohol2nitro.html



It said that they reported making several simple aliphatic nitroalkanes from nitrous acid and the alcohol via in situ generation of the nitrous by adding HCl to NaNO2.  Could it really be as simple as reacting EtOH with nitrous acid and getting the nitroethane?



Rhodium

  • Guest
wrong claim
« Reply #55 on: December 29, 2002, 06:08:00 AM »
I meant to remove that. Synlett published an article to refute the claims from that article. They were apparently mistaken, only the alkyl nitrites were formed, not the nitroalkanes.

https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroalcohol.pdf




El_Zorro

  • Guest
Weeeeell, shit. It looked so easy....
« Reply #56 on: December 29, 2002, 06:28:00 AM »
Weeeeell, shit.  It looked so easy....  I guess I should have figured it was too good to be true.


senzualus

  • Guest
:-(
« Reply #57 on: December 29, 2002, 09:59:00 PM »

Aurelius

  • Guest
Patent References US patent 4319059
« Reply #58 on: January 09, 2003, 04:58:00 PM »
Hope these are appreciated, takes a while to type them.

US 4319059

Preparation of Nitroalkanes

Abstract:

A process for making nitroalkanes in which an alpha-bromoalkanoic acid is reacted with an alkali metal nitrite, e.g. NaNO2, in the presence of the magnesium ion (Mg++) in an aprotic solvent to form a chelate.  Neutralization of the chelate with a mineral acid produces a nitroalkane having one less carbon atom than the reactant bromoalkanoic acid.


Other related Patents
US 2117931
US 3014972
US 3038015

Notes on the Reaction

aprotic solvent is used.  e. g. dimethyl sulfoxide
Mg compound can be MgSO4 (Epsom salts)
Use alpha- bromopropionic acid to receive nitroethane as major product
Potassium or sodium nitrites may be used
The catalyst (Mg compound) and the nitrite are used in slight molar excess
When the nitrite has been consumed in a molar amount equal to the initial molar amount of the bromoacid, the reaction can be considered complete.

Example 1:

To a mixture of magnesium methoxide (0.11mole) and dimethyl sulfoxide (50ml), alpha-bromopropionic acid (0.11mole) was added at 20*C with stirring.  To this mixture a solution of sodium nitrite (0.145mol) in dimethyl sulfoxide (65ml) was added at room temperature.  Then, the reaction mixture was stirred at room temp for 6 hours and was neutralized upon addition of diluted HCl.  The product was analyzed on a 3’x3/16” Poropak Q Column for nitroethane at 150*C and on a 3’x3/16” column packed with 10% ethylene glycol adipate and 1% phosphoric acid on Chromosorb AW 80/100 mesh for alpha-bromopropionic acid at 150*C.  This 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 a single run and 22 hours for a separate single run.  Reaction was conducted at room temp.  The run at 2 hours converted only 94.5% of the acid to yield 72.7% nitroethane.  The second run at 22 hours gave a conversion of >99% and a yield of 100% (QUANTITATIVE!!!!!)

At room temp the reaction apparently takes about 4-5 hours to go to completion.  At higher temps of 40-70*C the reaction time is shorter.  Thus, one or two hours (or even less at 75*C) will completely convert the bromoacid to the chelate to be decomposed to nitroethane by acidification with HCl.

When using dimethyl sulfoxide as solvent temperatures reaching 100*C should be avoided.  The solvent tends to volatize and decompose (violently) at 100*C.  Other aprotic solvents may not have this disadvantage.

Aurelius

  • Guest
Patent References US patent
« Reply #59 on: January 09, 2003, 05:00:00 PM »
US Patent 4431842

Catalytic Preparation of Nitroalkanes

Abstract:

A process of making nitroalkanes which comprises reacting a lower alkanol, e.g. methanol, and nitric acid (HNO3) in the vapor phase in the presence of a catalyst which is an oxide or a salt of a metal of Group II of the periodic table, e.g. Calcium Chloride.


Other related patents
US 2844634
US 2905724
US 3272874 – uses vapor phase nitration with nitric acid or nitric oxides with oxygenated sulfur compounds such as SO2 and H2SO4.
US 3113975- same as US 3272874 but includes the use of ozone.
US 3780115- nitration of paraffins by nitrogen peroxide (NO2)2 in the presence of oxygen (air) under pressure at 150-330*C.
US 3706808- reacting an olefin with nitric acid in the presence of a lower aliphatic monocarboxylic acid anhydride to produce a nitroester, subsequently reducing it with an alkali borohydride to form the nitroalkane.
US 3113975- use of ozone on amines to form nitro compounds

Representative Preparation of Catalyst

A catalyst was made by immersing an alumina support* in an amount of aqueous CaCl2 solution sufficient to completely wet it.  Excess water was evaporated and the catalyst dried.  The amount of CaCl2 supplied was sufficient to provide a 21% by weight  loading on the support.  Portions were calcined under a nitrogen purge (oxygen excluded) at 150*C, 415*C, 500*C, 600*C and 700*C each for a period of 4 hours.

* This was low surface area (<1 m^2/g) spherical support of medium porosity manufactured by Norton and designated SA-5205.

Example 1:

The different portions of the above prepared catalysts were run in the four foot reactor system.  Methanol conversion differed only slightly, varying rom about 13%-22% for the reaction run at 245*C, 5.5 sec contact time with a MeOH/HNO3/N2 ratio of 4/1/24.  Selectivity varied considerably for the reaction under the above conditions as is shown below in tabular form.

--------------------------------------------------------------------------------------------------------------------------
   Calcination Temp (*C)         % Selectivity to CH3NO2                
150   27
415   35
500   40
600   44
700   67
-------------------------------------------------------------------------------------------------------------------------


Not suggested as a practical method of home production of nitroalkanes.  This method was only posted for posterity.