Chemistry of Heterocycles. Part-IX Synthesis of lsoxazolylpyrazolones

Department of Chemistry, Kakatiya University, Warangal-506 009 Manuscript received 20 September 1983, revised 16 April 1984, accepted 15 February 1985 Isoxazolylpyrazolones (4) have been obtained by the heterocyolisation of ethyl-2­[1-phenyl-2-(3-methyl-4-nitro-5-isoxazolyl)ethyl]acetoacetates (3) with hydrazine hydrate. The latter have been produced by the Michaelation of 3-maityl-4-nitro-5-styryl­-isozazoles (2) with ethylacetoacetate in triethylamine. Interaction of the Michael adducts with phenylhydrazine gave only phenylhydrazones (6) instead of the N-phenyl­pyrazoIones (5)