Preparation of formic acid
AssigneeBASF SE
InventorsHeinz Hohenschutz, Johannes E. Schmidt, Hans Kiefer
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Abstract
Anhydrous or substantially anhydrous formic acid is prepared by hydrolyzing methyl formate in the presence of a formamide and then obtaining the formic acid from the hydrolysis mixture by distillation, by a method in which the hydrolysis is carried out in the presence of 0.5-3 moles, per mole of methyl formate, of a water-soluble formamide of the general formula I ##STR1## where R.sup.1 and R.sup.2 are each alkyl or together form an alkylene group, giving a 5-membered to 7-membered ring, with the proviso that the sum of the carbon atoms in R.sup.1 and R.sup.2 is 5 or 6 and, in the case of an alkylene group, a carbon atom which is not directly bonded to the N atom can be replaced by an oxygen atom.
Claims10
In a process for the preparation of anhydrous or substantially anhydrous formic acid by hydrolyzing methyl formate and then obtaining the formic acid from the hydrolysis mixture by distillation, the improvement which comprises:
- carrying out the hydrolysis in the presence of 0.5-3 moles, per mole of methyl formate, of a water-soluble formamide of the formula I ##STR3## where R.sup.1 and R.sup.2 are each alkyl or together form an alkylene group, giving a 5-membered to 7-membered ring, with the proviso that the sum of the carbon atoms in R.sup.1 and R.sup.2 is 5 or 6 and that, in the case of an alkylene group, a carbon atom which is not directly bonded to the N atom can be replaced by an oxygen atom.
Dependencies are inferred from the claim text.