Patrick A. Pié and, L. Marnett
Jul 1, 1988
Citations
0
Influential Citations
22
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Benzo[b]thiophenes substituted at the 3 position with methyl or carboxymethyl and at the 5 position with methyl, methoxy, chloro, bromo and nitro were prepared by cyclization of thiophenyl-acetals and ketones using a suspension of polyphosphoric acid in refluxing chlorobenzene. The overall efficiency of this method is superior to literature procedures because of the lower temperature and the limited amount of PPA used.