Kametani, Tetsuji published the artcileSyntheses of heterocyclic compounds. CCCLXXI. Synthetic approach to camptothecin, SDS of cas: 21190-89-6, the main research area is camptothecin analog; indolizinoquinoline; quinoline indolizino; pyrrolidinopyridone; pyridone pyrrolidino.
Picolinic acid 1-oxide was esterified with SOCl2 and EtOH to the Et ester, whose treatment with phosphoryl chloride gave Et 6-chloropicolinate (I). Hydrolysis of I with HCl gave 6-oxo-1,6-dihydropicolinic acid (II). Simultaneous condensation and cyclization of the Me ester of II with Me acrylate in the presence of sodium carbonate in DMF yielded the Me, 1,2,3,5-tetrahydro-1,5-dioxoindolizine-2-carboxylate (III). Hydrolysis and decarboxylation of III with HCl gave 3-oxo-pyrrolidino[2,1-f]-2-pyridone (IV). Friedlaender condensation of IV with 2-aminobenzaldehyde gave a camptothecin analog, 9,11-dihydro-9-oxoindolizino[1,2-b]quinoline (V).
Tetrahedron published new progress about camptothecin analog; indolizinoquinoline; quinoline indolizino; pyrrolidinopyridone; pyridone pyrrolidino. 21190-89-6 belongs to class pyridine-derivatives, name is Ethyl 6-chloropicolinate, and the molecular formula is C8H8ClNO2, SDS of cas: 21190-89-6.