T. Kametani, Hisao Nemoto, H. Takeda
1970
Citations
0
Influential Citations
15
Citations
Journal
Tetrahedron
Abstract
Abstract Picolinic acid 1-oxide (III) was esterified with thionyl chloride and ethanol to the ester IV, whose treatment with phosphoryl chloride gave ethyl 6-chloropicolinate (V). Hydrolysis of V with hydrochloric acid gave 6-oxo-1,6-dihydropicolinic acid (VI). Simultaneous condensation and cyclisation of the methyl ester of VI with methyl acrylate in the presence of sodium carbonate in dimethylformamide yielded the bicyclic ketoester (VIII). Hydrolysis and decarboxylation of VIII with hydrochloric acid gave 3-keto-pyrrolidino[2.1- f ]-2-pyridone (IX). Friedander condensation of IX with 2-aminobenzaldehyde gave the camptothecin analogue II.