A Synthetic Route to Bicyclic Pyrazolenines via 3-Chloropyrazolines and the Ring Openning of Pyrazolenines to Diazolakenes

Article abstract of DOI:10.1021/jo00286a022

Treatment of 5,5-disubstituted 3-chloro-1-pyrazolines, derived from the reaction between disubstituted diazomethanes and dimethyl chlorofumarate, with triethylamine gives the corresponding 3,3-disubstituted 3H-pyrazoles in good yield.This method was appli