The Vespiary

The Hive => Methods Discourse => Topic started by: tecnetium on September 11, 2001, 02:20:00 AM

Title: Possible MeOH and Formic acid synth
Post by: tecnetium on September 11, 2001, 02:20:00 AM

Hi bees have a look at this reaction swim found in one of her textbooks:

       50% NaOH
2HCHO -----------> CH3OH + HCOO-^Na+

Plain old formaldehyde can be used to make MeOH (a handy solvent) and sodium formate.

Clean up - Distill off MeOH (bp 65 C). Then distill off all the water. Then acidify with H2SO4 and distill off the formic acid (bp 100.5 C). Any comments?

Title: Re: Possible MeOH and Formic acid synth
Post by: Karl on September 11, 2001, 03:45:00 AM

The H2SO4 could oxidise the formic

Title: Re: Possible MeOH and Formic acid synth
Post by: Chromic on September 11, 2001, 04:19:00 PM

Maybe acidify with hydrochloric acid and boil off the azeotrope (which, btw has a higher BP than water or formic acid)?

Title: Re: Possible MeOH and Formic acid synth
Post by: Rhodium on September 11, 2001, 04:45:00 PM

Exactly, acidify just until neutral with HCl, and distill off the azeotrope (22.5% formic acid, 77.5% water) with a boiling point of 107.1°C (higher than that of formic acid, 100.8° C or water, 100°C). Make sure enough water is present, and collect the 105-110°C fraction.

Title: Re: Possible MeOH and Formic acid synth
Post by: PEYOTE on September 12, 2001, 05:28:00 AM

It's a simple dismutation....

Title: Re: Possible MeOH and Formic acid synth
Post by: Chromic on September 12, 2001, 06:25:00 PM

I take it 22% HCOOH can be used in a performic?

Title: Re: Possible MeOH and Formic acid synth
Post by: Rhodium on September 12, 2001, 06:34:00 PM

I'd suggest distillation of it first to achieve the above mentioned azeotrope. 22% seems a little bit low, but maybe it still would work with good agitation of the reaction.