N. Peet, S. Sunder, R. Barbuch
1986
Citations
1
Influential Citations
34
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
The Gewald syntheses were employed to prepare a series of 2-amino-3-carboethoxythiophenes, and the syntheses of two of these, namely, the 3,4-trimethylene (1f) and 3,4-tetramethylene (1g) derivatives, were examined in detail. In two preparations of 1f, octahydro-6a-(4-morpholinyl)-2-thioxocyclopenta[b]pyrrole-3-carboxylic acid (7) was a co-product. The structure of 7 was ascertained from its 300 MHz 1H nmr and 13C nmr spectra, and by its conversion to 1,4,5,6-tetrahydro-2-mercaptocyclopenta[b]pyrrole-3-carboxylic acid ethyl ester (8). Isolation of 7 and other observations led to postulated mechanisms for three of the Gewald thiophene syntheses.