The Reaction of Phosphorus Decasulfide with some Hydrazides and their Hydrazones: New Route for Construction of Four-membered, Five-membered, and Six-membered Phosphorus Heterocycles

Abstract

Reaction of some selected benzoic acid hydrazides 1a–c with phosphorus decasulfide P4S10 in dry pyridine afforded some novel pyridine solvate of 1,3,4,2-thiadiazaphospholes 2a–c. Similarly, treatment of their corresponding hydrazones 3a–c toward phosphorus decasulfide under the same reaction conditions gave the corresponding thio-analog 4 and 1,3,2-benzoxazaphosphinine and benzodiazaphosphinine pyridine solvates 5a,b, respectively. Treatment of (thio)semicarbazides and their corresponding (thio)semicarbazones with phosphorus decasulfide in dry pyridine yielded the novel 1,2,4,3-triazaphospholidines 6a,b, and 1,3,2-diazaphosphetidines 8a,b, respectively. Moreover, cyclization of (thio)carbohydrazides and their mono-(thio)carbohydrazones with phosphorus decasulfide produced 1,2,4,3-triazaphospholidines 9a,b and 11a,b, respectively. The structures of these products were confirmed from analytical and spectral data.