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Updated: Oct 25, 2026

Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines
Published on: January 3, 2018
Sulfur-Mediated Decarboxylative Thioamidation of α,β-Unsaturated Carboxylic Acids to Lactam-Derived Thioamides
Kaushal Kishor1, Shiv Chand1, Mayank Murthy1
1Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi221005, India.
Abstract:
An efficient and practical protocol has been developed for the synthesis of γ-lactam- and ε-caprolactam-derived thioamides through sulfur-mediated decarboxylative coupling of α,β-unsaturated carboxylic acids with DBN or DBU, accompanied by amidine ring opening. The transformation employs readily available and inexpensive starting materials and proceeds under transition-metal- and external-oxidant-free conditions. Control experiments and mechanistic studies support the involvement of sulfur-derived polysulfide intermediates and subsequent amidine ring opening. The operational simplicity and the use of elemental sulfur make this protocol a useful approach to lactam-derived thioamides.
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