Synthesis of pyrrolo[2,3-g]-and pyrrolo[3,2-f]quinolines from 5-amino-2,3-dimethyl-and 1,2,3-trimethylindoles with 4,4,4-trifluoroacetoacetic ester

Abstract

It has been shown that the condensation reaction of 5-amino-2,3-dimethyl-and 1,2,3-trimethylindoles with 4,4,4-trifluoroacetoacetic ester occurs either via the trifluoromethylcarbonyl or the ester group depending upon the conditions under which it is carried out. Under thermal conditions (refluxing in diphenyl) the enaminocrotonates formed are readily converted to pyrrolo[3,2-f]quinolines and the amides cyclize in trifluoroacetic acid at 78°C to give pyrrolo[2,3-g]quinolines.