Effective methods for the syntheses of 2??pyrazolines and pyrazoles from diazocarbonyl compounds

…, MR Colsman, RL Dorow

Index: Doyle, Michael P.; Colsman, Mark R.; Dorow, Roberta L. Journal of Heterocyclic Chemistry, 1983 , vol. 20, p. 943 - 946

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Citation Number: 19

Abstract

Abstract Dipolar addition of diazocarbonyl compounds to α, β-unsaturated esters and nitriles in the presence of pyridine results in the production of 2-pyrazolines in nearly quantitative yields. In one case, reaction of α-diazoacetophenone with acrylonitrile, Michael addition of the 2-pyrazoline to the conjugated olefin is observed, but this process is minimized by limiting the amount of pyridine employed. 5-Cyano-2-pyrazolines are converted to ...