Synthesis and Reactions of 4, 6—Diaryl— 2,3,4,5-Tetrahydropyridazin-3-ones

Abstract

The hitherto unknown 4,6-diaryl -2,3,4,5-tetrahydro-pyridazi n-3-ones (Il)a-e were synthesised from the a-aryl , B-aroylpropionic acids (I)a-e either by their reaction with hydrazine hydrate or by their conversion to a,y-diaryl- 'Ltenol treatment of the latter with hydrazine hydrate. ( I l) afforded 3-chloropyridazine derivative (IV) on its reaction with POCI PCI 3' The 3-chl oropyridazine was treated either with sodium azide producing the tetrazolopyridazine derivative (V) or with acylhydrazines to give the triazolopyridazine derivatives (Vl)a-c. 3-Acy1pyridazines (Vll)a & b were obtained on treataent of (Il ) with acetyl chloride. (Il)a was converted¯to its corresponding thione (VI Il), also reacted with benzyl amine giving 3-N-benzy1pyridaz ine (l X). (Il)a was dehydrogenated to the corresponding dihydropyri dazinone