S. Schneller, J. Petru
1974
Citations
0
Influential Citations
8
Citations
Journal
Synthetic Communications
Abstract
Abstract A present concern in this laboratory is the relationship of thieno-[2,3-b]- (I) and thieno[3,2-b]thiophene (II) ring systems to the sulfur analogs1,2 of various biologically active indoles. Since the present routes to I3 and II4 are low yielding processes, we have found it imperative to devise a pathway whereby we can obtain these compounds in synthetically useful quantities. Therefore, due to the similarity of I and II with benzo[b]thiophene, it was concluded that the halogen promoted cyclization of α-mercaptocinnamic acids 1,2b,5 to benzo[b]thiophene-2-carboxylic acids would be advantageous for this objective.