Synthesis of some heterocyclic systems of anticipated biological activities via 6-aryl-4-pyrazol-1-ylpyridazin-3-one

Abstract

6-Aryl-4-pyrazol-1-ylpyridazin-3-one (1) reacted with PCl 5/POCl3 mixture to give 3-chloropyridazine derivative (3). Reaction of (3) with 2-hydroxybenzoylhydrazide and semicarbazide hydrochloride afforded (5) and (7). Reaction of (1) with ethyl chloroacetate gave (10). Reaction of (10) with hydrazine hydrate yielded the hydrazide (11). The hydrazide (11) condensed with the acetylenic ketones and esters (12a-d) and acetylacetone (16) to give the adducts (13a,b,14,15&17). Reacting (1) with formaldehyde and piperidine or morpholine or piperazine, 3-bromopropanoic acid, acetic anhydride, p-toluenesulphonyl chloride or succinyl chloride or oxalyl chloride or ethanolamine gave the adducts (19-21), (23-27). The structures of all the newly synthesized compounds were evidenced from their spectral and microanalytical data.