Mechanistic observations in the gewald syntheses of 2‐aminothiophenes
Norton P. PeetMerrell Dow Research Institute, Indianapolis Center, 219 Building 9550 Zionsville Road, Indianapolis, Indiana 46268Shyam SunderMerrell Dow Research Institute, Indianapolis Center, 219 Building 9550 Zionsville Road, Indianapolis, Indiana 46268Robert J. BarbuchMerrell Dow Research Institute, Indianapolis Center, 219 Building 9550 Zionsville Road, Indianapolis, Indiana 46268Anna P. VinogradoffWestern Applied Science and Technology Laboratories, The Dow Chemical Company, Loveridge Road, Pittsburg, California 94565
1986en
ABI
Аннотация
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 1 H nmr and 13 C 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.
Ҳали таржима қилинмаган
Идентификаторлар
Иқтибослар ва манбалар
2 та иқтибос0 та фойдаланилган манба