Regioselective Synthesis of Polysubstituted Pyrazoles and Isoxazoles
作者:Alan R. Katritzky、Mingyi Wang、Suoming Zhang、Michael V. Voronkov、Peter J. Steel
DOI:10.1021/jo0101407
日期:2001.10.1
A regioselectivesynthesis has been developed for the preparation of unsymmetrical 1,3,5-triaryl-4-alkylpyrazolines and -pyrazoles by treatment of alpha-benzotriazolyl-alpha,beta-unsaturated ketones with monosubstituted hydrazines followed by alkylation at the 4-position of the pyrazoline ring. Reaction of alpha-benzotriazolyl-alpha,beta-unsaturated ketones with hydroxylamine gives 3,5-disubstituted