[Siddy]

Hi, im a long time reader, first time writer.

Ive got a question, from a 2nd year chem subject, its from a very old past exam paper. I doubt it will be asked again, but i cant work it out.
Unfortunately its a hard copy thats on reserve in the library, but i think i remember the jist.

List the reaction, catalysts' and environment necessary for the following:

-Methanol > Methanoic Acid (Formic Acid).


I know a reaction with CO(g) will form Methyl Formate, and then Hydrolysis with H20 will form Methanoic Acid. But i cant think of a direct route with no intermediate.
There are some other questions in that section and all have NO intermediate, so i assume you are not supposed to use one (ie, methyl formate). This is also the easier section of the exam so it really annoying that i cant figure it out.
Does anyone have any practice knowledge of formic acid synthesis?

[lavoisier]

Siddy, I found this link:

http://www.springerlink.com/content/u50r1q4q1r738364/

to a paper where they describe the direct production of HCOOH from MeOH, but it's a biotechnological process, not really a purely chemical one, going through HCHO.

Patents as recent as 2001 still describe the methyl formate route, OK, with improvements, but still...
Or maybe the direct process already exists, but for some reason it's extremely difficult to find any details about it.

If your teacher knows a direct route, he should either let the world know, or patent it and become a billionaire! ;-)

[Yggdrasil]

Will Jones reagent not work?

[Dan]

I first thought of the Jones reagent, or a permanganate, but after reading Lavoisier's post I thought a bit harder - do you think further oxidation to carbonic acid (<--> CO₂ + water) could be an issue with the direct oxidation of methanol with such oxidising agents?

[Siddy]

Yatta! Im thinking it might be a poorly written questions now, thanks for the replies.

lavoisier, indeed that reaction will be under biotech. But thanks, its quite interesting (currently looking for the full length article or patent).

As for Jones reagent, this is my understanding:

R-CH2-OH + Jones reagents -> R-CHOOH

To me that mean Ethanol > Ethanoic acid is the smallest carbon chain possible.
Does anyone know if thats right?
(Jones reagents: CrO3, H2SO4, Acetone.)

I think this warrants an email to my lecturer. I will report back.

[Siddy]

Ok, my lecturer said he did not write the question. When the question was reviewed in the process of writing his exams he found it undefinitive.

An answer he would accept requires intermediates, and the only single reaction has very low yields and is a multi stage reaction.

Does anyone have experience in Methanol to Methyl Formate (with CO).
Like environment conditions and catalysts.
Just out of interest.

[lavoisier]

For the reaction via methyl formate, you can look in wikipedia or even in www.uspto.gov under the patent search section. Basically they do a base-catalysed addition of MeOH to CO, but you'd better check, I just had a quick look at it.

I excluded any laboratory method, like chromium-based oxidations, not because I was worried about HCOOH reacting further (though I wouldn't be surprised if it did - it's a pretty strong reducing agent), but because I was answering Siddy's initial question, where a catalytic (and most likely industrial) process was discussed.