Author Topic: Easy Formic Acid Synthesis  (Read 3073 times)

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foxy2

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Easy Formic Acid Synthesis
« on: December 06, 2001, 02:28:00 AM »
Here is a very easy oxidation of formaldehyde to formic acid using peracetic acid.  I would rather do this than the synth from oxalic acid.

Formic acid.    
Yasuda, Kiyoshi; Goto, Yukihisa.

Patent JP52113911

(in Japanese)

Abstract 

HCO2H was prepared by liquid-phase oxidation of HCHO with MeCO3H at >100°C. Thus, 150 mL/h 29% MeCO3H in AcOEt was added to 100g 37% aqueous HCHO containing 10% MeOH over 5 h at 40°C with 0.8 mol ratio of MeCO3H/HCHO to give HCO2H with 99.1% conversion and 98.5% selectivity.

foxy2

  • Guest
Re: Easy Formic Acid Synthesis
« Reply #1 on: December 06, 2001, 10:29:00 AM »
These articles indicate that you cannot synthesize formic acid by oxidation of methanol or formaldehyde with potassium permanganate, as the formic acid would be ozidized further to carbon dioxide and water.

A kinetic study of the autocatalytic permanganate oxidation of formic acid.
Perez-Benito, Joaquin F.; Arias, Conchita; Brillas, Enrique.   
Int. J. Chem. Kinet.  (1990),  22(3),  261-87. 

Abstract

The results of the title study indicate that this reaction is autocatalyzed by both manganese(II) ion (formed as a reaction product) and colloidal manganese dioxide (formed as an intermediate).  The apparent rate consts. corresponding to the noncatalytic and autocatalytic reaction pathways are obtained.  The activation energies assocd. with the true rate consts. were also derived.  The percentage of the total reaction corresponding to each pathway is given for typical exptl. conditions.  Mechanisms in agreement with the kinetic data are proposed for the six different reaction pathways obsd. 


Conditions for acetic acid purification from formic acid by potassium permanganate or dichromate.    
Fedoseeva, Z. K.; Freidlin, G. N.
Khim. Prom.  (1956),  306-7.

Abstract

A 5% excess of oxidizing agent over the theoretically required amt. is sufficient for the HCO2H oxidation.  Vigorous stirring shortens the reaction and improves the results.  A revolution no. in the soln. of 6208, calcd. from the mixer revolution rate, is found to be the optimum for oxidation.  A single treatment with KMnO4 or K2Cr2O7 reduces the HCO2H concn. in AcOH to 0.1%, a double treatment to 0.06%.  Higher temp. favors the oxidation rate. 

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Rhodium

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Re: Easy Formic Acid Synthesis
« Reply #2 on: December 06, 2001, 06:16:00 PM »
Is it easy to separate formic and acetic acid, as the final reaction mixture seem to contain 50/50 of the two acids (I am now referring to the first post in the thread)?

Osmium

  • Guest
Re: Easy Formic Acid Synthesis
« Reply #3 on: December 06, 2001, 07:28:00 PM »
Separating the formic and acetic acid isn't trivial, but maybe there is no need to separate the two, just use the resulting acid mixture for another run to decrease the acetic acid content each time. Maybe it is possible to start with HCO3H instead of the acetic acid, so you will end up with HCOOH only?

What bothers me much more is how to prepare a 29% solution of MeCO3H in EtOAc...

Greensnake

  • Guest
preparation of peracid solutions
« Reply #4 on: December 06, 2001, 08:05:00 PM »
Quite nice method for preparation of peracid solutions -

Journal of Organic Chemistry, 1959, Vol 23, N 12, pp. 1823-1826

Read it carefully and you will be enlightened (some right glassware strongly reccomended tho)

Edit: This article has been posted in

Post 460155

(Rhodium: "Prep of anhydrous peracetic acid solutions", Newbee Forum)
/Rhodium

goiterjoe

  • Guest
Re: Easy Formic Acid Synthesis
« Reply #5 on: December 07, 2001, 02:06:00 AM »
would this reaction work for paraformaldehyde?

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