Heterocyclic fused 2, 5-dihydrothiophene S, S-dioxides as precursors to heterocyclic o-quinodimethanes

LM Chaloner, APA Crew, PM O'Neill, RC Storr…

Index: Chaloner; Crew; O'Neill; Storr; Yelland Tetrahedron, 1992 , vol. 48, # 37 p. 8101 - 8116

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Citation Number: 36

Abstract

2, 5-Dihydrothiophene 5, 5-dioxides 8 and 6 have been obtained by interception of flash- pyrolytically produced 2, 3-dihydro-2, 3-bis (methylene) thiophene with sulfur dioxide and from methyl 4, 5-bischloromethylthiophene-2-carboxylate by reaction with sodium sulfide and oxidation. Pyrazole fused analogues 15 and 16 (R= Me and COPh) were prepared from 3-phenylsulfonyl-2, 5-dihydrothiophene S, S-dioxide by cycloaddition of diazomethane, ...