Ai-Long Fan, S. Cao, Jing-Hua Xu
Mar 1, 1998
Citations
0
Influential Citations
3
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
A new sulfonyl group-containing heterocyclic compound 2-(2-chloro-4-nitrophenylsulfonyl)-1-(2-thienyl)ethanone 2 was prepared from the corresponding sulfide 2-(2-chloro-4-nitrophenylthio)-1-(2-thienyl)ethanone 1. Two different cyclization reactions of the compound 2 were discussed. In contrast to the tandem alkylation-cyclization process [1], another cyclic procedure was described. In the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene as a base and dimethylformamide as a solvent, compound 2 was treated with ethyl acrylate or methyl methacrylate at 50–55° to give the 1,4-benzoxathiin 4,4-dioxide 5 or 6 respectively via a tandem Michael conjugate addition-cyclization process.