Solvent-free three component synthesis of N-Acyl hydrazone derivatives from the reaction between aldehydes and α‚β-unsaturated esters

Acylhydrazones are one of the most important Schiff bases and have been well documented to possess important pharmacological activities such as antitumor,1 antibacterial,2 antiviral, and antimalarial.3 Due to the pharmacophoric character of acylhydrazone, this group framework has been widely exploited in the design of new bioactive compounds with different pharmacological profiles.4At present study, we wish to introduce a novel, efficient and green method for the synthesis of new acyl hydrazide derivatives via reaction of various acylhydrazones with α,β-unsaturated esters (Fig. 1).In this protocol, the desired benzoyl-2-(2-phenylethylidene) hydrazinyl)propanoates (4) were synthesized by the aza-Michael addition of hydrazide (1) and aldehydes (2) to activated acrylates (3) in the presence of tetrabutyl ammonium bromid (TBAB) –an ionic organic salt– and DABCO at 80°C under solvent-free condition.

Keywords:

N-Acyl hydrazine , Acyl hydrazide , Solvent-free reaction