A novel and efficient synthesis of N,N-dialkylaminoisopropyl- and O-alkylisopropyl-2-(1-alkyl-2-oxopropylidene)phosphonohydrazido oximes--potential marine fish toxin analogues. Part 1.

A novel and efficient method for the synthesis of N,N-dialkylaminoisopropyl- and O-alkylisopropyl-2-(1-alkyl-2-oxopropylidene)phosphonohydrazido oximes (4) using activated silica as dehydrating agent has been developed. The reaction involves the condensation of substituted diacetyl monoxime and N,N-dialkylaminoisopropyl-phosphono hydrazide or O-alkylisopropylphosphono hydrazides and gave the corresponding analogues of a naturally occurring fish toxin in excellent yields under mild conditions.