204977-82-2Relevant academic research and scientific papers
A general synthesis of quinoline-2,5,8(1H)-triones via acylation of 2,5- dimethoxyaniline with S-tert-butyl thioacetates by application of the Knorr cyclization
López-Alvarado, Pilar,Avenda?o, Carmen,Menéndez, J. Carlos
, p. 186 - 194 (2007/10/03)
An efficient synthesis of quinoline-2,5,8(1H)-triones bearing alkyl groups at C3 and/or C4 is described. The reaction sequence employed involves Knorr cyclization of 2,5-dimethoxyanilides into 5,8- dimethoxyquinoline systems, followed by oxidative demethylation with cerium ammonium nitrate. The starting 2,5-dimethoxyanilides were prepared by chemoselective acylation of 2,5-dimethoxyaniline with a series of β-oxo thioesters obtained by regioselective alkylation of S-tert-butyl acetothioacetate (1) at C2 and/or C4. The introduction of electrophiles other than alkyl groups at C2 on 1 was also studied.
