Reaction of aromatic aldehydes with 1,2-dibenzylhydrazine

Abstract

The reactions of 1,2-dibenzyIhydrazine with several aromatic aldehydes in refluxing toluene gave the benzaldehyde dibenzylhydrazones (9) and (1 3) in high yield. It is suggested from labelling studies and from the failure to trap an azomethine imine in the reaction between dibenzylhydratine and benzaldehyde that such intermediates are not involved in the formation of the hydrazones. These products may be formed directly via hydride transfer in the hydrazinocarbinol(l8) or the hydrazonium ion (1 9).Reactions between 1,Zdisubstituted hydrazines (1) and aldehydes (2) have been investigated by several groups, mainly with the objective of generating azomethine imines (4) (Scheme 1). The earliest reports on the use of 1,Zdiarylhydrazines were