NOVEL SYNTHESIS OF 4-AROYL-6-PHENYLPYRIDAZIN-3(2H)-ONES

4-Aroyl-6-phenylpyridazin-3(2H)-ones (4a-c) were synthesized by the oxidation of the corresponding 4-arylmethyl-6-phenylpyridazin-3(2H)-ones (3a-c) using sodium dichromate in glacial acetic acid. The reactions of 4a-c with hydrazine hydrate and hydroxylamine hydrochloride proceeded smoothly to give the corresponding hydrazones (5) and oxime (6). 4a-c reacted with dimethyl sulphate to give 4-aroyl-2-methyl-6-phenylpyridazin-3(2H)-ones (7a-c), respectively while their reaction with phosphorus oxychloride gave 4-aroyl-3-chloro-6-phenylpyridazines (9a-c), respectively.