Synthesis of 1-substituted 5-aryl-3-styryl-2-pyrazolines and 3-aryl-5-styryl-2-pyrazolines by the reaction of dibenzylideneacetones and E,E-cinnamylideneacetophenones with hydrazines

摘要

The reaction of dibenzylideneacetones or E,E-cinnamylidene- acetophenones and hydrazine hydrate provided 1-propionyl derivatives of 5-aryl-3-styryl-2-pyrazolines and 3-aryl-5-styryl-2-pyrazolines. These unsaturated ketones afforded 1-(2-carboxyphenyl) or 1-(4-carboxyphenyl) 5-aryl-3-styryl-2-pyrazolines and 1-(4-carboxyphenyl) derivatives of 3-aryl-5-styryl-2-pyrazolines on treatment with (2-carboxyphenyl)hydrazine or (4-carboxyphenyl)hydrazine in hot acetic acid. Structures of all new 2-pyrazolines have been elucidated by microanalyses and a combined utilization of various spectroscopic methods.