The Reaction of N-(Phenylsulfonyl)benzohydrazonoyl Chloride with Enamines

Abstract

3-(Diethylamino)crotonic acid esters and 1-diethylamino-1-cyclohexene react with N-(phenylsulfonyl)benzohydrazonoyl chloride to give substituted pyrazoles in 87–89% and 1.4% yields, respectively, the corresponding morpholine enamines affording no pyrazoles. The pyrazole formation is interpreted in terms of a step-by-step process involving the nucleophilic attack of the enamines on the hydrazonoyl chloride.

An Approach to Polysubstituted Triazipines, Thiadiazoles and Thiazoles Based on Benzopyran Moiety Through The Utility of Versatile Hydrazonoyl Halides as In Vitro Monoamine Oxidase Inhibitors

“…Hydrazonoyl halides are quite reactive reagents, which could react with different functional groups such as thiol, amino, NH, and active methylene groups. Examples for the ring systems that have been synthesized from hydrazonoyl halides are pyrazoles, thiazoles , imidazoles , triazoles , thiadiazoles , and tetrazines . On the other hand, the benzopyran moiety is an important heterocyclic structure in synthetic and biological applications , also, benzopyrans posses a quite inhibitory activity against monoamine oxidase .…”