Sciencemadness Discussion Board - Ammonium formate from Ammonium chloride

Ammonium formate from Ammonium chloride

B.D.E - 24-9-2019 at 16:34

Hey there,

So I need to get some ammonium formate for the Leuckart reaction, and the only ammonium source I've got is NH4Cl.

I'm guessing that NH4Cl won't react with HCOOH under STP condition..
But is there any easy to get catalysts/common reagents that might get the reaction going?

Also, is it possible to instead react NH4Cl with HCOONa? And if so, how would you separate it from the NaCl?

Much thanks! :)

[Edited on 25-9-2019 by B.D.E]

hodges - 24-9-2019 at 17:15

Mix the ammonium chloride with a strong base such as NaOH. Heat slightly or add a small amount of water. Bubble the evolved ammonia gas into the HCOOH.

B.D.E - 24-9-2019 at 18:07

Quote: Originally posted by hodges

Mix the ammonium chloride with a strong base such as NaOH. Heat slightly or add a small amount of water. Bubble the evolved ammonia gas into the HCOOH.

draculic acid69 - 24-9-2019 at 19:24

Quote: Originally posted by B.D.E

Quote: Originally posted by hodges

Mix the ammonium chloride with a strong base such as NaOH. Heat slightly or add a small amount of water. Bubble the evolved ammonia gas into the HCOOH.

Thanks for the reply.
I thought about it, but I figured that the efficiency would be pretty low due to the poor kinetics of liquid-gas reactions. Was I wrong?

I can also get my hands on some formamide.
Is there a way to use it as a precursor of ammonium formate?

You can get formamide and you want to turn it into ammonium formate? That's kind of a backward step isn't it.you can use formamide in the leuckart you know that right?
Or are you trying to use the ammonium formate directly? I've heard it works but whether or not it works better I can't say.

B.D.E - 25-9-2019 at 07:06

Quote: Originally posted by draculic acid69

Quote: Originally posted by B.D.E

You can get formamide and you want to turn it into ammonium formate? That's kind of a backward step isn't it.you can use formamide in the leuckart you know that right?

Or are you trying to use the ammonium formate directly? I've heard it works but whether or not it works better I can't say.

I know that formamide can also be used as the Leuckart reagent, but from what I've read the yield is much lower compared to that obtained by the ammonium formate method.

In addition, my ketone has some steric hindrance, which might make the formamide method even less efficient.

I saw in wikipedia(see attached picture) that the following reaction might take place:
HCONH2 + H2O --> HCOOH4N(I guess the rxn is in equilibrium?).

Is it really that simple? If anyone have some relevant data to share it would be swell

Pumukli - 25-9-2019 at 07:44

Hodges said it.
The absorbtion of ammonia will be 100%!

Poor kinetics of liquide-gas reactions?
Not in this case!
Ammonia likes water very much, but likes formic acid even more!
Actually I think your problem will be how to moderate the reaction, unless you want to end up with a thick, white, ammonium-formate smoke and dealing with massive suck-back(s)!

draculic acid69 - 25-9-2019 at 08:07

Yeah definitely suckback and thick rxn solution with product vapor being the only things that will kill yeild. If you use a coke bottle between your nh3 generator and the formic acid it'll deal with any suckback and using a cold dilute solution will stop excessive product vapor and product precipitating.

Praxichys - 25-9-2019 at 08:45

You can always use a gas washing bottle to absorb the ammonia directly into ice-cold water to eliminate issues with reaction heat and viscosity. You can easily get to >20wt% like this, and the resulting solution can then be carefully neutralized with formic acid.

Alternatviely, I have made acetamide by refluxing acetic acid with urea, and similar amides follow suit. Formamide should follow this formula, using formic acid and urea. It takes a while but can be left largely unattended, and the reagents are dirt cheap which might work with the excess you need for your Leukhart over the formate. Just a thought.

S.C. Wack - 25-9-2019 at 15:59

Quote: Originally posted by B.D.E

how would you separate it from the NaCl?

Volatility

B.D.E - 26-9-2019 at 00:17

Thanks for the new information everyone!

I'll probably go with the "bubbling ammonia method".

Quote: Originally posted by S.C. Wack

Quote: Originally posted by B.D.E

how would you separate it from the NaCl?

Volatility

But they're both solids.

S.C. Wack - 26-9-2019 at 02:53

NH4Cl was made by sublimation and it has been said that the formate can be distilled with vacuum...what happens when ammonium formate is distilled without vacuum?

Metacelsus - 26-9-2019 at 03:41

It decomposes to formamide and water.

[Edited on 2019-9-26 by Metacelsus]

S.C. Wack - 26-9-2019 at 15:59

Of course it does, so it requires vacuum fractionation next. Small amounts of various cpds. are known to increase yields when using the dry result.

[Edited on 27-9-2019 by S.C. Wack]

B.D.E - 14-11-2019 at 12:25

UPDATE:
Well.. I tried bubbling ammonia gas trough formic acid solution(<99%) and I got jack shit :S.

This is what i've tried:
>In an erlenmeyer flask I mixed NH4Cl&NaOH in a mol/mol ratio of 1:1(at this point without any water present).
>To the erlenmeyer I've connected a "vacuum takeoff" adapter with a rubber hose and a glass funnel at the end of it.
>I placed the funnel inside a beaker full of cold formic acid solution(99%, 1/2 eq). The beaker was placed into a cold water bath.
>I added ~10ml of non distilled water to the erlenmeyer and turned on the heating. The reaction started after a few minutes and than gradually got more and more vigorous(it never got too crazy though). I lifted the funnel from the solution(just for a few seconds) and a white "fog" had appeared(as expected).

The bubbling stopped after about ~15-20 minutes, and suck-back have occurred(the upside down funnel did its job). Almost no ammonium formate was precipitate in the beaker. In addition, there were still a lot of powder left in the erlenmeyer. probably meaning not all the NH4Cl have reacted.

I've tried the all thing again with the same amounts of reagents(1:1:~0.5*), but this time with a more water(also none distilled). *I used the same solution of formic acid from the first try.
After bubbling stopped, it didn't seemed as if more ammonium formate had participated, and like the first try - there were still a lot of powder left in the erlenmeyer(this time there was also a strong smell of ammonia coming from the erlenmeyer.

[Edited on 14-11-2019 by B.D.E]

TheMrbunGee - 14-11-2019 at 13:08

Quote: Originally posted by B.D.E

UPDATE:
Well.. I tried bubbling ammonia gas trough formic acid solution(<99%) and I got jack shit :S.

This is what i've tried:
>In an erlenmeyer flask I mixed NH4Cl&NaOH in a mol/mol ratio of 1:1(at this point without any water present).
>To the erlenmeyer I've connected a "vacuum takeoff" adapter with a rubber hose and a glass funnel at the end of it.
>I placed the funnel inside a beaker full of cold formic acid solution(99%, 1/2 eq). The beaker was placed into a cold water bath.
>I added ~10ml of non distilled water to the erlenmeyer and turned on the heating. The reaction started after a few minutes and than gradually got more and more vigorous(it never got too crazy though). I lifted the funnel from the solution(just for a few seconds) and a white "fog" had appeared(as expected).

The bubbling stopped after about ~15-20 minutes, and suck-back have occurred(the upside down funnel did its job). Almost no ammonium formate was precipitate in the beaker. In addition, there were still a lot of powder left in the erlenmeyer. probably meaning not all the NH4Cl have reacted.

I've tried the all thing again with the same amounts of reagents(1:1:~0.5*), but this time with a more water(also none distilled). *I used the same solution of formic acid from the first try.
After bubbling stopped, it didn't seemed as if more ammonium formate had participated, and like the first try - there were still a lot of powder left in the erlenmeyer(this time there was also a strong smell of ammonia coming from the erlenmeyer.

[Edited on 14-11-2019 by B.D.E]

Ammonium formate Solubility in water
(grams per 100g of water)

102g (0 °C)
142.7 g (20 °C)
202.4 g (40 °C)
516 g (80 °C)

unionised - 14-11-2019 at 13:31

I'm fairly sure that mixing solutions of sodium formate and ammonium chloride in wet methanol would produce a ppt of NaCl.

Might be interesting to try.

B.D.E - 15-11-2019 at 09:02

Quote: Originally posted by unionised

I'm fairly sure that mixing solutions of sodium formate and ammonium chloride in wet methanol would produce a ppt of NaCl.

Might be interesting to try.

Very interesting idea. I think I'll try it, but with dry methanol and sodium formate instead. Hoping that the methanol-formate solution would be enough to dissolve the NH4Cl. If not I will slowly add water to the mixture.

Thanks mate

B.D.E - 16-11-2019 at 15:13

Screw that shit. I'll just buy ammonium carbonte or urea(for NH3 gas generator). I spent way too much time on trying to use NH4Cl.

Quick report: First I tried to dissolve sodium formate in a dry methanol solution. It is soluble but only slightly(20gr of HCOONa didn't fully dissolved in ~250ml of 50°C methanol, not even close). I tried adding dH2O slowly using a pipette but I ended up using something like ~150ml until everything(HCOONa&NH4Cl) got dissolved(after heating it up).

At that point I realized the methanol doesn't have any real use due to the large amounts of water present. So I boiled it off and continued heating the aqous solution to a boil. I boiled off large portion of the water and let the solution cool. a white ppt fell from the solution. I decanted the leftover water and washed the white ppt twice with diethyl ether. NH4Cl&HCOONa are insoluble in ether, while HCOONH4&NaCl are soluble. I distilled the ether to dryness but there weren't any significant amount of salts to be found(only a tiny bit, similar to what you get after boiling off 100ml of tap-water).

If I were to repeat this process, I would have tried to reflux the solution for about 12 hours or so, to see if it will make any difference. Also I might have used soxhelt extractor with the ether, in order to make sure I fully dissolved all the NaCl&HCOONH4 out of the ppt. But to be honest, I'm not sure if it would work even than, and it just doesn't worth the time.

Keep in mind that it is also possible that I just fucked something up in the process, I'm still a beginner after all. But due to the simplicity of the alleged reaction, I found it hard to believe I fucked things up so badly to a level I didn't got any measureable amount of NaCl&HCOONH4 out of the ether...

Good night :S

mackolol - 17-11-2019 at 13:37

Quote: Originally posted by B.D.E

Screw that shit. I'll just buy ammonium carbonte or urea(for NH3 gas generator). I spent way too much time on trying to use NH4Cl.
I decanted the leftover water and washed the white ppt twice with diethyl ether. NH4Cl&HCOONa are insoluble in ether, while HCOONH4&NaCl are soluble. I distilled the ether to dryness but there weren't any significant amount of salts to be found(only a tiny bit, similar to what you get after boiling off 100ml of tap-water).

If I were to repeat this process, I would have tried to reflux the solution for about 12 hours or so, to see if it will make any difference. Also I might have used soxhelt extractor with the ether, in order to make sure I fully dissolved all the NaCl&HCOONH4 out of the ppt. But to be honest, I'm not sure if it would work even than, and it just doesn't worth the time.

Keep in mind that it is also possible that I just fucked something up in the process, I'm still a beginner after all. But due to the simplicity of the alleged reaction, I found it hard to believe I fucked things up so badly to a level I didn't got any measureable amount of NaCl&HCOONH4 out of the ether...

Good night :S

I don't know where did you read this but no salt is soluble in ether. Thats biggest bullshit I have heard.
I think that just bubbling ammonia through formic acid will do the job but don't expect any precipitate to form. Just distill this solution off, under vacuum for the best results until but be careful as ammonium formate decomposes at 180C and melts at 116C. Maybe better option will be just adding acetone or some alcohol to the mother liquor and the salt should precipitate off then due to lower polarity of solvent.

S.C. Wack - 17-11-2019 at 15:00

Quote: Originally posted by mackolol

I think that just bubbling ammonia through formic acid will do the job but don't expect any precipitate to form.

"The ammonium salt was prepared by passing ammonia into 90% formic acid. Towards the end of the absorption, the temperature was raised sufficiently to ensure the deposition of the neutral (instead of the acid) salt. The product obtained was recrystallized from absolute alcohol and then desiccated over 99%) sulfuric acid in vacuo. The melting point of the final material was 117.3C"

B.D.E - 18-11-2019 at 14:13

Quote: Originally posted by mackolol

Quote: Originally posted by B.D.E

Scre...

First of all,thanks for the reply and for the willing to help. I was surprised too about the ether solubility but I found a few sources clearly stating that HCOONH4 is indeed soluble in ether:
http://chemister.ru/Database/properties-en.php?dbid=1&id...
http://www.intox.org/databank/documents/chemical/ammform/cie...
http://www.sciencemadness.org/smwiki/index.php/Ammonium_form...
(just to name a few)

As for NaCl I only found a few unverified sources, but I didn't looked into it too much because I didn't really cared about it. I would definitely going to check it myself whenever I'll succeed in making some HCOONH4 myself.

As for your comment on the ammonia method, I actually a bit embarrassed for not thinking on the solubility of the HCOONH4 in formic acid... I mean I did cooled it to just above the melting point of formic acid, but even then the solubility is extremely high... Unfortunally, just after reading your post I've tried crushing out the solution I've made with >95% ethanol and nothing had precipitate. It was kind of a rushed testing with only few ml(it's late at night and I don't want to get too much into it right now). I will probably try it again tomorrow or sometime during the week.

But I still doubt that I'll get anything significant out of it. Not because bubbling ammonia in formic acid is a bad method, but because I had troubles liberating significant amounts of ammonia gas from ammonium chloride(as mentioned in a previous post in this thread).

I also saw that NurdRage just released a video on a similar issue he encountered, only in his case he used ammonium nitrate instead. He eventually switched to urea for better yield of ammonia gas. That's why if I won't be able to get ammonium carbonate I will buy some urea instead(as also been mentioned on the same previous post).

[Edited on 18-11-2019 by B.D.E]

Tsjerk - 18-11-2019 at 23:18

How do you generate ammonia from ammonium chloride? Mixing the chloride with excess NaOH and slowly adding water should do the job.

I wouldn't go for crashing out with lower alcohols here as ammonium formate is soluble in them.

I once prepared ammonium formate with concentrated ammonia and concentrated formic acid. This works fine but drying was a b*tch. If you have ether the extraction of the formate from dry NH4Cl and sodium formate sounds interesting. You could try to stir a mixture in ether for some days.

[Edited on 19-11-2019 by Tsjerk]

B.D.E - 19-11-2019 at 04:37

Quote: Originally posted by Tsjerk

How do you generate ammonia from ammonium chloride? Mixing the chloride with excess NaOH and slowly adding water should do the job.

I wouldn't go for crashing out with lower alcohols here as ammonium formate is soluble in them.

I once prepared ammonium formate with concentrated ammonia and concentrated formic acid. This works fine but drying was a b*tch. If you have ether the extraction of the formate from dry NH4Cl and sodium formate sounds interesting. You could try to stir a mixture in ether for some days.

[Edited on 19-11-2019 by Tsjerk]

I tried exactly that, only with equivalent amount of NaOH. Later today I would try crushing out the solution with toluene. Hopfully I would get something out of it.

Tsjerk - 19-11-2019 at 07:24

Toluene will just give you a two phase system, nothing in your mixture is miscible with it.

B.D.E - 19-11-2019 at 14:41

Quote: Originally posted by Tsjerk

Toluene will just give you a two phase system, nothing in your mixture is miscible with it.

Yeah you're right. But weird enough I tried crushing the solution both with acetone and with ether(on separate tries), and both times I've gotten a two layer system. I decided just pouring it to a crystalizing dish and leaving it for a while on minimal heating. I hope that by this time tommorow it would be done evaporating and I'll be left with at least some ammonium formate. If not I'll probably be putting this on hold for a while.

Cheers.

[Edited on 19-11-2019 by B.D.E]

[Edited on 20-11-2019 by B.D.E]

nimgoldman - 20-11-2019 at 09:32

You can most likely get Baker's ammonia (ammonium bicarbonate), listed as E503 on foodstuffs. It's OTC as people use it for baking cakes.

Simply slowly add your formic acid over the powder, in portions to prevent excessive bubbling, stir and perhaps heat the beaker a bit as the reaction is endothermic.

The procedure is shown in Nile Red's YT video though he used lab grade ammonium carbonate.

Since the baker's ammonia is only food grade, you might need to recrystallize it from absolute ethanol or water. Drying is possible with vacuum desiccator and H2SO4, but drying with heat will melt the crystals.

If you really have to use ammonium chloride, I am afraid you will need strong base to liberate the ammonium as it won't leave the chloride ion easily. With a short path for the gas it might improve the efficiency. Note that you don't need dry ammonia in this case.

[Edited on 20-11-2019 by nimgoldman]

stoichiometric_steve - 20-11-2019 at 17:15

I will gladly sell you some Ammonium Formate. U2U me.

Tsjerk - 20-11-2019 at 23:02

Quote: Originally posted by B.D.E

. I decided just pouring it to a crystalizing dish and leaving it for a while on minimal heating. I hope that by this time tommorow it would be done evaporating and I'll be left with at least some ammonium formate. If not I'll probably be putting this on hold for a while.

Cheers.

[Edited on 20-11-2019 by B.D.E]

I wouldn't count on getting a crystalline compound overnight, it is really hygroscopic. Maybe if the air where you are drying is really low in moisture, or the heat is high enough. What temperature is "minimal" in your case?

B.D.E - 21-11-2019 at 11:08

Thanks for all the tips and advices, but I'm quite happy to say that after about 2 days of slow evaporation(no heat whatsoever), I did get some significant amount of precipitate which is most likely to be ammonium formate

I might try it again in the future, but for now I think I've got enough ammonium formate for my purposes. Also I would probably prefer to just use the ammonium carbonate method just to avoid the realtivly hassle in a liquid-gasous reaction. I am glad I've experienced with it though.

Anyway, thanks for all the help and ideas. I appreciate it(!).

https://imgur.com/Atxe6St

[Edited on 22-11-2019 by B.D.E]