Synthesis of ethylidene bis-formamide using formic acid

摘要

Ethylidene bis-formamide, a precursor for the monomer N-vinylformamide, is made in high yield by heating together formamide and acetaldehyde in a mol ratio of at least 3:1 and in a reaction mixture which is at least 20 weight percent formic acid. In a preferred procedure the acetaldehyde is added after the formamide has been preheated and formic acid is present. Yields of ethylidene bis-formamide of over 50%, based on the acetaldehyde, are obtained in relatively short reaction times, before loss of substantial amounts of recoverable formamide through hydrolysis.