The Reaction of Thiophene 1,1-Dioxide With Haloform-Sodium Hydroxide Under Phase-Transfer Catalysis

Abstract

3,4-Dibromotetrahydrothiophen 1,1-dioxide (2) reacts in the reagent system chloroformaqueous sodium hydroxide-benzyltriethylammonium chloride to give 3-dichloromethylene-2,3-dihydrothiophen 1,1-dioxide (6a), for which low-temperature X-ray structural data are presented. Bromoform may be substituted for chloroform to give the corresponding dibromomethylene compound (6b) in good yield.