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Updated: Aug 24, 2026

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
Published on: June 23, 2019
Efficient synthesis of imidazoles from aldehydes and 1,2-diketones using microwave irradiation
Scott E Wolkenberg1, David D Wisnoski, William H Leister
1Department of Medicinal Chemistry, Technology Enabled Synthesis Group, Merck Research Laboratories, P.O. Box 4, West Point, Pennsylvania 19486, USA. scott_wolkenberg@merck.com
Abstract:
[reaction: see text] A simple, high-yielding synthesis of 2,4,5-trisubstituted imidazoles from 1,2-diketones and aldehydes in the presence of NH(4)OAc is described. Under microwave irradiation, alkyl-, aryl-, and heteroaryl-substituted imidazoles are formed in yields ranging from 80 to 99%. Short syntheses of lepidiline B and trifenagrel illustrate the utility of this approach.
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