Author Topic: Meyer disproportionation reaction (Read 174 times)

reDEEMed · « **on:** September 24, 2011, 05:38:05 AM »

I can't find much on this and I'm wondering if it's because the Meyer part is unnecessary. Anybody ever heard of it? I was reading about the synthesis of hydroxylamine and I found a post on another board where someone posted three different routes to hydroxylamine, none of which I am familiar with. The first route he mentions is this disproportionation reaction. Like many syntheses you read online it reads really simple, but I'm not buying it, it can't be as simple as it sounds. This single sentence synthesis says that heating nitromethane with sulfuric acid gives formic acid and hydroxylamine sulfate. If this is true, and it is this simple, this is perhaps the coolest thing I've ever seen. I don't have any formic acid, I sure would like some. If I can take these two compounds which I do have and end up with two new compounds I would like to have, I call this a win in every sense of the word. The way I've hit a wall here just googling the reaction this guy cites, the aroma of bullshit is really starting to hang thick in the air.

Has anyone heard of this reaction? If there were any truth to it, how would the stoic work out? I'd be willing to go straight myth busters on it if I had some understanding of how it should work, so I understand the stoic for it etc. I'm scouring March's for any mention of disproportionation now, but still any help would be greatly appreciated.

Anybody willing to throw me a bone here?

dingbow · « **Reply #1 on:** September 26, 2011, 12:02:10 PM »

Are you referring to thread on PS?

One of the members on PS tried this at a small scale and claimed success. I would suggest trying the same, 5ml scale. When I have the need for more hydroxylamine, I will be trying it small scale.

Of interest may be US Patent 2749217, and also US Patent 3380807.

dingbow · « **Reply #2 on:** September 26, 2011, 12:10:54 PM »

Actually, this may be what your after:
hxxp://pubs.acs.org/doi/abs/10.1021/ie50349a025

reDEEMed · « **Reply #3 on:** September 27, 2011, 12:18:15 AM »

Thanks dingbow, I'll check those out as soon as I get a chance. I got so many irons in fire I have to rotate to give them all a chance and this fell out of rotation a day or so ago, but it's coming back up soon! I spent all night last night (12hrs) refluxing nitromethane, acetic and HCl acids. If anyone plans to try this I will tell you now that a closed system is a must. That fucker gassed hard the entire time and I was running a 500mm graham condenser with ice water. That was being vented into a sodium bicarb solution. I bet I got 10 pounds of salt lol. I am definitely down for another way to make hydroxylamine. I really wanna make some formaldoxime but until I can make hydroxylamine in big chunks, I'm just not willing to risk what I have. Apparently the trimer is quite prized. Fuck it, why not. I got nothing else to do.

dingbow · « **Reply #4 on:** September 27, 2011, 02:08:10 AM »

The original method in GAA and HCl is no good, it gives an impure product and wastes GAA.

You are correct, the sealed system is a lot better. A thick walled glass bottle running a stir bar works much better. Only need HCl and your nitro-paraffin, giving two phases, which as conversion takes place eventually becomes homogeneous and alerts you to full conversion.

The salt precipitates under cold conditions without the need to distill giving ~40% yield. This yield would go up somewhat if some water was removed under distillation, though I never bothered.

reDEEMed · « **Reply #5 on:** September 27, 2011, 03:20:12 AM »

I wish I had someone irl to work with and hang out with that was into chemistry. It seems like anyone I do meet is either into nothing but drugs and they don't really give a fuck about chemistry or they are all about the chemistry and any mention of drugs they don't want anything to do with you.

I guess online will have to do. But, I think I would dig hanging out with a few of you irl. I like your unwillingness to give up. The try try try again thing is an honorable mindset imo. It's not too common these days in the microwave generation. If it doesn't come quick and easy with minimum effort yet giving maximum payoff, most people seem uninterested. Maybe I'm just getting old and crotchety, but this generation annoys me.

That is completely off topic, I know. But it was on my mind and I figure shitting in my own thread is acceptable.

/rant

dingbow · « **Reply #6 on:** September 27, 2011, 07:31:28 AM »

a lab buddy would be good, a lab 'bitch' even better lol

reDEEMed · « **Reply #7 on:** September 27, 2011, 09:38:08 AM »

Dude, I would literally kill in cold blood for a nerdy cool chick. I was talking to this girl where I lived before that was a chemist, but she was too uptight. All she ever did was worry about her job. Wouldn't smoke a joint or anything, so that was fail. I don't think such an animal exists, at least that's what I would rather believe since I can't have one.

dingbow · « **Reply #8 on:** September 27, 2011, 11:18:19 AM »

oh they do exist, but yeah not exactly dime a dozen.

But by 'lab bitch' I wasnt necessarily referring to a persons sex, but rather anyone who does all the dirty work for ya, like cleaning your glassware

Anyway, if you do make up some hydroxylamine sulfate, let us know how you go.

reDEEMed · « **Reply #9 on:** September 27, 2011, 12:21:21 PM »

I plan on trying every method that is within my reach. The nitro/acetic/Hcl reflux is simple enough, but it used quite a bit of materials in relation to yield. Although to be fair, I don't have a final number yet, it seems to still be crashing out. Plus the setup takes longer and ties up more of my glass.

Do you always make yours or what? I still wanna either prove or disprove my aldehyde>carboxylic acid>amide route. It just requires using some things I'm not comfortable using in my kitchen. But like I said, next month I'll be in a new house with a dedicated lab and I'll have a lot less to worry about.

dingbow · « **Reply #10 on:** September 27, 2011, 12:48:13 PM »

Yeah I always make mine. The yield sucks to be sure and forming the crystals takes overnight (x3), so its a lengthy procedure as well. But doing it in a sealed bottle saved me doing any distillation, gave a purer product and avoided use of hard to obtain GAA. Though the purity was really realised through the absense of GAA contamination.

Personally I would be more interested in:
aldehyde + grignard -> secondary alcohol + oxidation -> ketone

I think that might work, though if monomethylation works (and right now I have high hopes it will), it wont matter that much to me anymore.

I have formed the carboxylic acid by the way, through basic hydrolysis of the amide. Not really what your after, but if you want some carboxylic acid to just play with, its an easy route.

reDEEMed · « **Reply #11 on:** September 27, 2011, 01:29:43 PM »

Nah, only interested in the acid because it would be on it's way to the amide in the scenario I was talking about. GAA is hard for you to get? I can't imagine it being half as scarce as nitromethane. My local science store sells 99% acetic acid, which is what I used. What did you mean by 3x, that it took 3 nights for you?

dingbow · « **Reply #12 on:** September 27, 2011, 02:46:52 PM »

local science store? No such thing in these parts!

Nitromethane used to be available OTC in 99% form, for those in the RC hobby that mixed their own fuel. They have slowly started to disappear though, I think due to lack of sales, but its still available from some specialty shops.

Yeah so chill overnight to form crystals, filter then chill the solution again overnight, filter and repeat once more. Each time yielding less, overall coming to around ~40%.

reDEEMed · « **Reply #13 on:** September 27, 2011, 03:57:15 PM »

Just to verify that my pics are no longer dragging metadata around with them, here are pics of my setup and first pull of crystals.

Wizard X, anything now? I had to use exiftool, since both of those programs you linked are for windows.

Edit: How do you dry your crystals? Straight up air dry? Also, what can they be rinsed or rextalized with? Mine have a yellow cast, I would like to get rid of that yellow. Even if there was no yellow I would still want to rextalize just to know I had the purest product I could have. So, I guess in a nutshell, how do you purify yours?

Edit 2: Thanks for requesting that ref. When I saw there was a reply in that thread it reminded me I needed to request that one. Imagine my surprise when the reply was the ref because you had already requested it! My first pull is dry and in the bottle, 24.5gms. I definitely want to clean them up somehow. I hate the reek of acetic acid.

Wizard X · « **Reply #14 on:** September 28, 2011, 12:09:57 AM »

Quote from: reDEEMed on September 27, 2011, 03:57:15 PM

Wizard X, anything now? I had to use exiftool, since both of those programs you linked are for windows.

Okay now!

atara · « **Reply #15 on:** September 28, 2011, 01:19:03 AM »

Quote from: shroomedalice

hey guys been playing with a patent on making hydroxylamine sulfate made from sulfuric acid and nitromethane
neat.

well got it too work and it kills all cladenstine methods of making this substance.

in a 500ml flask was placed 125 ml of nitromethane.

this is refluxed and stirred.

when solution is refluxing 125ml of sulfuric acid is slowly (yes I mean fucking slowly) dripped into

the solution.

addition of sulfuric acid should take about 1 too 2 hours.

entire reaction should take 5 hours from time drip starts.

when 5 hours is compleated add mixture to equal weight alcohol and leave to cool.

filter out quantitive yeild of hydroxylamine from nitromethane.

this is the cheapest and quickest way known. it is also the most space efficient making

the whole small lab size idea more of a reality.

I was able to make over half a kilo in a day in a 500ml flask.

note of caution though this reaction releases carbon monoxide.

the condensor must be conected to a gas exaust of some kind that is feed

out side.

if you dont understand why carbon monoxide is dangerous for fucks sake do some reading.

other than that its a peice of cake.

~originally posted on WD back in the day, hope swisa doesn't mind me posting this here...

reDEEMed · « **Reply #16 on:** September 28, 2011, 01:49:32 AM »

Dude, you are a fucking saint! Thank you!

I was wondering about ol' Alice the other day, aint seen him around.

lugh · « **Reply #17 on:** September 28, 2011, 02:19:57 AM »

The thread from the Hive concerning this reaction:

Chemistry Discourse

Posts 1 - 18 of 18

foxy2
(Distinctive Doe)
09-21-01 19:42
No 216070
Make Formic Acid and Hydroxylamine in one step!!

Hello boys and girls. I am happy to report that we have found ourselves a winner here!!!

Ahheemmm

To 200 mL of methanol were added 30 grams of nitromethane and 60 grams of oxalic acid. The resulting mixture was stirred to form a solution. The solution was then refluxed at atmospheric pressure at a temperature ranging from 60 to 70C(refluxing), for 20 hours. Hydroxylamine and formic acid were obtained.

United States Patent 3,380,807
Current U.S. Class: 423/387; 562/606

Now isn't that handy???
Seems a wee bit better than the synth at Rhodium's.
I know SO2 and Barium salts are fun and all butttt....

Oh Yea
Post reaction I think you can crash out hydroxylamine sulfate with H2SO4, assumeing the solution is not to wet. Or you can baseify and vacuum distill out the hydroxylamine freebase. Then add H2SO4 and distill your formic!!

Do Your Part To Win The War

catastrophe
(Hive Bee)
09-21-01 21:06
No 216093
Re: Make Formic Acid and Hydroxylamine in one step!!

Nice! Shit, you are like a fox!
Anything about yields?

Antibody2
(Hive Addict)
09-21-01 21:50
No 216102
Re: Make Formic Acid and Hydroxylamine in one step!!

sweet indeed foxy ,

i wonder whether the bases used(NaAc or Na2HCO3) for oximation would still be required if starting from the freebase? or would the hydroxylamine form a formate salt, complicating workup?

"All those memories lost like rain..."

Rhodium
(Chief Bee)
09-21-01 22:03
No 216104
Re: Make Formic Acid and Hydroxylamine in one step!!

Ketone + HONH2 (freebase) => Oxime + water. If you use the freebase, the base should not be necessary.

If hydroxylammonium formate is fully soluble in methanol, then a sparingly soluble salt could be made by the addition of the appropriate acid. The freebase can be vacuum distilled (bp 58°C at 22 mmHg) but is unstable in its freebase form and should be converted into a salt as quickly as possible.

lugh
(Hive Bee)
09-21-01 22:24
No 216105
Caution!!!

Isolation of hydroxylamine free base can be problemetical (besides the explosion risk), normally this leads to decomposition into ammonia. One procedure that has worked is to form the phosphate and distill under diminished pressure [Ann. 307, 333 (1899) & 311, 117 (1900)]. This reaction was originally discovered by Victor Meyer, some more related references are: Ann. 180, 163 (1876); J. Prakt. Chem., (2) 7, 480 (1873) & (2) 8, 309 (1873) & Ber. 10, 776 (1877)

halfapint
(Ubiquitous Precursor Medal Winner)
09-22-01 09:38
No 216166
hydroxylamine & formic

CRC says hydroxylamine formate melts at 76o, decomposes at 80. When it does, hydroxylamine (b.p. 56.5o) is already in the vapor phase, whether Lugh has cautioned us about it or not. I want to see that patent, but espace is down right now. Very curious to know what they say about recovery of the products. foxy2 could have saved us all a lot of worry, by sketching in some of these details... Well, it says oh yea up there now. Either foxy2 edited while I was posting, or I just overlooked it.

If the two products do salt each other (well they do, no doubt) then acid hydrolysis is probably called for, distilling off the formic acid and leaving the hydroxylamine as its salt. This takes Lugh's caution into account. I never realized hydroxylamine is liquid in such a narrow temperature range: mp 33, bp 56. The free base is a solid at room temp.

turning science fact into <<science fiction>>

Rhodium
(Chief Bee)
09-22-01 09:56
No 216167
Re: Caution!!!

The hydroxylamine freebase bp quoted by me was at 22 mmHg. The mp of hydroxylamine freebase is 33°C.

A suggestion for isolation would be to (as you said) add HCl to the reaction mixture, and distill off the formic acid together with the methanol. The residue that could be crystallized from the concentrated mother liquor would be the hydrochloride salt.

lugh
(Hive Bee)
09-22-01 10:12
No 216168
Re: Make Formic Acid and Hydroxylamine in one step

Reported melting points for the pure hydrochloride salt are between 151-7 degrees C

Rhodium
(Chief Bee)
09-22-01 10:14
No 216169
Re: Caution!!!
US Pat 3,380,807

Preparation of hydroxylamine and monocarboxylic acids from primary nitroparaffins and oxalic acid

Abstract

A process for preparing hydroxylamine and moncarboxylic acids by reacting a primary nitroparaffin, for example 1-nitropropane, with oxalic acid.

This invention relates to a process for the production of hydroxylamine and monocarboxylic acid. In a particular aspect this invention relates to a process for the production of hydroxylamine and monocarboxylic acid by reacting a primary nitroparaffin with oxalic acid.

In U.S. Patent 2,381,410, it is disclosed that hydroxylamine and monocarboxylic acid are obtained by heating a primary nitroparaffin and hydrochloric acid in the presence of a monocarboxylic acid. Acetic acid, propionic acid arid butyric acid are specifically mentioned for use in the process. It is stated in the patent that the monocarboxylic acid of use in the process served principally as a solvent for the primary nitroparaffin and the hydrochloric acid.

In the prior art process the hydroxylamine is obtained as the crystalline salt of hydrochloric acid (hydroxylamine hydrochloride). When other forms of hydroxylamine are desired it is necessary to dissolve the crystalline salt in a suitable solvent such as water or methanol and then convert the hydroxylamine to the desired form.

It is an object of the present invention to provide a process for the production of hydroxylamine and monocarboxylic acid.

A further object of the present invention is the provision of a process for the production of hydroxylamine and monocarboxylic acid without the employment of hydrochloric acid in the reaction step.

Further objects and advantages of the present invention will be apparent from the specification and the appended claims.

It has been discovered in accordance with the present invention that monocarboxylic acid and hydroxylamine are obtained by reacting a primary nitroparaffin with oxalic acid without the employment of hydrochloric acid in the reaction step. Acetic acid, propionic acid and butyric acid are not successfully employed as the organic acid of use in the present invention. The reaction results in the conversion of the primary nitroparaffin to the corresponding monocarboxylic acid and to hydroxylamine. For example, propionic acid and hydroxylamine result from the reaction of 1-nitropropane and oxalic acid. The reaction is illustrated as follows:

1-nitropropane + oxalic acid => propionic acid + hydroxylamine

The nitroparaffins of use in the present invention are primary nitroparaffins that is to say nitroparaffins where-in the nitro group is bonded to a carbon atom which is in turn bonded to at least two hydrogen atoms. Typically suitable primary nitroparaffins are represented by the formula R-N02 wherein R is an alkyl radical having from one up to about seven carbon atoms. Representative primary nitroparaffins include nitromethane, 1-nitrohexane, nitroethane, 1-nitropropane, 1-nitropentane, 1-nitrobutane, 1-nitroheptane, etc., and the like. Monocarboxylic acids prepared from such typical primary nitroparaffins are represented by the formula R-NO2 wherein R is an alkyl radical having from one up to about six carbon atoms. Representative monocarboxylic acids prepared in accordance with the present invention include formic acid, acetic acid, butyric acid, propionic acid, etc., and the like.

In accordance with the present invention a primary nitroparaffin and oxalic acid are reacted to obtain hydroxylamine and monocarboxylic acid. The process of the invention is suitably carried out by heating the primary nitroparaffin and the oxalic acid under reflux conditions, preferably in the presence of an inert solvent, that is to say a solvent inert to the reactants and the reaction products. Examples of such solvents are water, methanol, ethanol, propanol, butanol, etc., and the like. The use of methanol is preferred. A weight ratio of solvent to reactants of in excess of 2:1, for example from about 5:1 to about 20:1, is typically employed.

The temperatures employed in the present invention may vary and will depend among other things on the particular nitroparaffin employed and on the particular inert solvent employed. For example, when the reaction is carried out under reflux conditions with methanol as the solvent and 1-nitropropane as the nitroparaffin, temperatures in the range of about 60 to about 70° C. are typically employed at atmospheric pressure. When butanol is substituted for methanol as the solvent of the process, temperatures in the range of about 115 to about 125° C. are typically employed at atmospheric pressure.

The mole ratio of oxalic acid to primary nitroparaffin is of importance in the present invention. While hydroxylamine and monocarboxylic acid are obtained at lower ratios, best results are obtained when the mole ratio of oxalic acid to primary nitroparaffin is in excess of 1:1, for example in the range of about 2:1 to about 5:1.

The hydroxylamine and monocarboxylic acid produced according to the process of the present invention may be recovered from the reaction medium by any suitable procedure. For example, the hydroxylamine may be recovered as free hydroxylamine by neutralization of the reaction medium with a suitable base followed by distillation of the neutralized reaction medium under reduced pressure to remove the free hydroxylamine. The hydroxylamine may also be precipitated from the reaction medium as the salt of oxalic acid by cooling and concentrating the reaction medium. The hydroxylamine may also be recovered as the salt of a strong mineral acid such as sulfuric acid or hydrochloric acid by methods known to the art.

The invention will be understood more fully by reference to the specific examples. It is understood that the examples are presented for purposes of illustration only and are not inteaded as a limitation of the invention.

Example 1

To 200 ml. of methanol were added 30 grams of 1-nitropropane and 60 grams of oxalic acid. The resulting mixture was stirred to form a solution. The solution was then refluxed at atmospheric pressure at a temperature ranging from about 60 to 70° C. for 20 hours. Hydroxylamine and propionic acid were obtained.

Example 2

The procedure of Example 1 was repeated with the exception that at the end of the 20-hour period aqueous hydrochloric acid was added to the reaction medium. The reaction medium was then distilled to remove propionic acid. The distilled reaction medium was then evaporated to dryness under vacuum. Hydroxylamine hydrochloride was obtained.

Example 3

The procedure of Example 1. is repeated in all essential details with the exception that 1-nitroethane is substituted for 1-nitropropane and butanol is substituted for methanol. Acetic acid and hydroxylamine are obtained.

Example 4

The procedure of Example 1 is repeated in all essential details with the exception that nitromethane is substituted for 1-nitropropane. Formic acid and hydroxylamine are obtained.

Example 5

The procedure of Example 1 is repeated in all essential details with the exception that 1-nitrobutane is substituted for 1-nitropropane. Butyric acid and hydroxylamine are obtained.

foxy2
(Distinctive Doe)
09-22-01 18:24
No 216229
Re: Caution!!!

I assumed people could look up the patent easily on their own(www.uspto.gov) because I have no way to easily convert TIFF files to text and typeing the whole thing is not my idea of fun!

lugh warned that distilling hydroxylamine freebase is an explosion hazard, therefore I would avoid this unless you know how its done properly(I would assume a strong vacuum, but don't know)

So how in the world can we get nice hydroxylamine freebase for reacting with a keytone??

There is a procedure for hyrooxylamine freebase in alcohol solvent. I will get better details when I can. Here is an overview of what i remember.

Hydroxylamine Freebase in Alcohol
Hydroxylamine sulfate(powdered) is dispersed in 50/50 methanol/propanol, it does not dissolve. Ammonia gas is bubbled in to convert hydroxylamine sulfate to freebase, which dissolves, while precipitateing ammonium sulfate. When you think you are done, add a bit more hydroxylamine sulfate to consume any leftover NH3. Then filter off any solids, ammonium sulfate and unreacted hydroxylamine sulfate. The result is a relatively pure hydroxylamine freebase in alcohol.

Hows that???

Do Your Part To Win The War

Dr_Sister
(Hive Bee)
09-22-01 18:42
No 216238
sweeeeeet!

Sweet, that's how, whatta kickass thread! this one's certainly earned a spot on my CD! you two have improved my mood immeasurably!

7.10.01

Rhodium
(Chief Bee)
09-22-01 18:44
No 216240
Re: sweeeeeet!

Please report back any experimental details using this method, I believe the patent is pretty sketchy, especially when it comes to the isolation of the hydroxylamine as a salt.

foxy2
(Distinctive Doe)
09-22-01 18:47
No 216243
Hydroxylamine freebase in water

Here is a procedure for aqueaous freebase. I assume hydroxylamine(bp 107C) distills over with water(bp 100C) thus limiting the explosion hazard. However this could be very dangerous also. I don't have the exact details of the patent only the abstract.

Japanese Patent JP2000211906

PROBLEM TO BE SOLVED: To provide an aqueous solution of free hydroxylamine essentially free from salts and organic materials and having high purity and high concentration.
SOLUTION: This process for producing an aqueous solution of free hydroxylamine comprises the reaction of an aqueous solution or slurry containing hydroxylammonium sulfate with an alkali to form an aqueous solution or slurry containing free hydroxylamine and a dissolved or partly precipitated sulfate, the mixing of the obtained aqueous solution or slurry with a lower alcohol to precipitate a solid sulfate, the separation of a liquid containing the lower alcohol and a part of water by the distillation of the aqueous solution after the separation of the solid sulfate and the distillation of the residual liquid to obtain the aqueous solution of free hydroxylamine as the distillate.

Do Your Part To Win The War

foxy2
(Distinctive Doe)
09-22-01 18:55
No 216248
Re: sweeeeeet!

Rhodium
The sulfate salt is not soluble in alcohol, therefore adding H2SO4 and ppt it should be realatively simple. I assume oxalic acid and formic are fairly soluble in the alcohols. I can think of nothing else that would ppt from H2SO4 except maybee some residual NH3?

Do Your Part To Win The War

foxy2
(Distinctive Doe)
09-23-01 06:37
No 216361
Another possible purification

Continuous purification of hydroxylammonium salts. Kalab, Vladimir; Mazurova, Alzbeta; Cuciak, Jozef. Povazske Chem. Zavody, N. P., Zilina, Czech. Chem. Prum. (1976), 26(3), 123-5. CODEN: CHPUA4 Journal written in Czech. CAN 85:162604 AN 1976:562604 CAPLUS

Abstract
The soln. of hydroxylammonium salt contg. high concns. of acid and ammonium salts is treated with a ketone to form an oxime. The oxime is extd. with trichloroethylene and then the oxime-trichloroethylene soln. is treated with an acid soln. to form a more pure hydroxylammonium salt.

(Preparation); PREP (Preparation) (purifn. of, acetone in)

Do Your Part To Win The War

foxy2
(Distinctive Doe)
09-23-01 06:47
No 216362
More Info and possibilities!!

Preparation of hydroxylamine and aldehydes from alkali metal salts of primary nitroparaffins and organic acids.

US Patent 3386803

Abstract
H2NOH and aldehydes are produced by the reaction of a water-sol. alkali metal salt of a primary nitroparaffin with HCO2H or oxalic acid, optionally in the presence of an inert solvent. Thus, a soln. of 10 g. PrNO2 and 4 g. NaOH in 100 ml. water was added slowly to 50 ml. HCO2H and the mixt. stirred 90 min. and combined with aq. HCl to give EtCHO and 51% H2NOH.HCl. A soln of 10 g. PrNO2 and 4 g. NaOH in 100 ml. water was added slowly to 25 g. oxalic acid in 200 ml. MeOH and the mixt. treated as above to give EtCHO and H2NOH. Similar treatment of EtNO2 and BuNO2 gave the corresponding aldehydes and H2NOH.

Do Your Part To Win The War

foxy2
(Distinctive Doe)
09-23-01 06:53
No 216363
Hydroxylamine freebase in Alcohol

Here is the reference I promised

Manufacture of pure hydroxylamine or solutions thereof.

German Patent DE 1247284

Abstract
Hydroxylammonium chloride has been used heretofore for making H2NOH because of its soly. The cheaper hydroxylammonium sulfate (I) is suitable for the manuf. of H2NOH by making a fine suspension of I in an alc. contg. (shows a less than or equal to sign) 3 C and treating with NH3. The insol. I that remains and the (NH4)2SO4 formed in the reaction mix are readily sepd. Thus, finely ground I 246 g. is suspended with stirring in a mixt. of MeOH 250 and PrOH 250 ml. and NH3 is introduced at a rate of 20 l./hr.; the temp. rises from .apprx.20° to 45° and after .apprx.3 hrs. the reaction ceases as can be noted by the escape of NH3. An addnl. 20 g. of I is added and the mixt. is stirred for another hr. After cooling, the excess I and (NH4)2SO4 are filtered off to provide a soln. of H2NOH 95.7 g., corresponding to a yield of 89.2%.

Do Your Part To Win The War

foxy2
(Distinctive Doe)
01-31-02 14:52
No 263353
Re: Hydroxylamine freebase in Alcohol

Hydroxylamine purification via ion exclusion.
US 4147623

Abstract
NH2OH is sepd. from aq. solns. contg. H3NOH+ salts in mixt. with salts of cations whose corresponding bases have been dissocn. consts. ³10-7. The aq. soln. is adjusted to pH 6-11 and then the soln. is passed through a cation-exchange resin bed loaded with charge-compensating ions which compose a base or an anion-exchange resin or with charge-compensating ions which compose an acid. A 1st effluent is removed from the bed contg. predominantly cations eluted from the cation exchange resin or anions eluted from the anion-exchange resin. A later effluent contg. NH2OH is obtained.

Cation/Anion Exchange Resins are otc if you know where to look.

Preparation of high-purity hydroxylamine sulfate from an impure solution.
RO 95695
Patent written in Romanian.

Abstract
An impure dil. soln. contg. hydroxylamine sulfate is treated with acetone or MEK at pH 6-7 and 50-100°, the oxime formed is extd. with CCl4, C2H4Cl2, or C2H2Cl4 and then hydrolyzed by boiling with 5-15% H2SO4 or HCl soln. High-purity (e.g., 98%) hydroxylamine sulfate is isolated by known methods (e.g., crystn.).

Fully Informed Jury! (http://www.fija.org/)

Posts 1 - 18 of 18

http://www.the-hive.ws forum@the-hive.ws

dingbow · « **Reply #18 on:** September 28, 2011, 02:54:06 AM »

Quote from: reDEEMed on September 27, 2011, 03:57:15 PM

Edit: How do you dry your crystals? Straight up air dry? Also, what can they be rinsed or rextalized with? Mine have a yellow cast, I would like to get rid of that yellow. Even if there was no yellow I would still want to rextalize just to know I had the purest product I could have. So, I guess in a nutshell, how do you purify yours?

Edit 2: Thanks for requesting that ref. When I saw there was a reply in that thread it reminded me I needed to request that one. Imagine my surprise when the reply was the ref because you had already requested it!

The hydrochloride salt of hydroxylamine is quite hygroscopic and will become quite wet in open atmosphere. I dried mine infront of a heat lamp, though I noticed some slight decomposition occurred. The product you have looks really wet, too wet to dry infront of a heat lamp effectively.

I rinse with 96% EtOH, works a charm and removes acid residue, I do not find the need to recrystalise (note though that I dont use GAA). I suggest you put it into a vac buchner, rinse with EtOH 3-4x. This should dry it considerably and allow heat lamp drying.

If your intent on recrystalisation, a mixture of EtOH/H20 should work. Alternately, dissolve with minimum warm H20, crash out with 3x volume EtOH.

Yeah I was interested in seeing it myself so couldn't wait and requested it myself

slightly off topic, but very cool to see an old hive master here

reDEEMed · « **Reply #19 on:** September 28, 2011, 03:20:24 AM »

Not sure if this has been posted elsewhere or not. It kinda seems familiar, but not really. Anyway, it's a good addition to this thread.

Edit: You're right, a rextal is unnecessary. A single wash with EtOH did a mighty fine job. Brilliantly white and no longer smells like nuclear vinegar.

Glyoxime, Diaminofurazan and some Energetic Derivatives, by A XT

Author Topic: Meyer disproportionation reaction (Read 174 times)

reDEEMed

Meyer disproportionation reaction

dingbow

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dingbow

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dingbow

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dingbow

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dingbow

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reDEEMed

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dingbow

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dingbow

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