Formamides e.g. diethylformamide are prepared by reacting a primary or secondary amine e.g. diethylamine or ammonia with (a) an alkyl formate or (b) carbon monoxide and an alkanol in the presence, as catalyst, of (i) a compound containing an amidine group or (ii) a Group V element-containing Lewis base and an epoxide. The Lewis base can be a trivalent nitrogen or phosphorus-containing compound. The amidine group which can be cyclic or acyclic can form part of a guanidine group.
A commercially economical process for preparing a carboxylic acid ester from a carboxylic acid amide is disclosed. The process is very meritorious, since it produces neither ammonia nor ammonium sulfates. Rather, the process by-produces formamides which are very useful compounds as solvents. Further, formamide can easily be converted to hydrogen cyanide by dehydration. The process comprises reacting a carboxylic acid amide with a formic acid ester and/or methanol and carbon monoxide in the presence of a bicyclic amidine or tertiary amine catalyst and optionally in the co-existence of a metal carbonyl. An industrial process for preparing methyl methacrylate which is a materialization of the process shown above is described in detail referring to a figure.
