Carbon Tetrachloride → HCID 59394014, compound

Participants

Reaction Steps

To a solution of the mixture of 4-Oxo-4,5,6,8-tetrahydro-3H-pyrido[3,4-d]pyrimidine-6,7-dicarboxylic acid 7-tert-butyl ester 6-ethyl ester and 4-Oxo-3,5,7,8-tetrahydro-4H-pyrido[4,3-d]pyrimidine-6,7-dicarboxylic acid 6-tert-butyl ester 7-ethyl ester (1.5 g, 4.64 mmol) in DCE (25 mL), carbon tetrachloride (1.34 mL, 13.9 mmol) and triphenylphosphine (2.43 g, 9.28 mmol) are added. The reaction is heated at reflux and after completion of reaction as judged by LCMS. The solvents are removed and the products are isolated using FCC eluting with heptane:EtOAc 80:20. At this point the two products are separated. 4-Chloro-5,8-dihydro-6H-pyrido[3,4-d]pyrimidine-6,7-dicarboxylic acid 7-tert-butyl ester 6-ethyl ester MS (ESI) m/z 342.1 (M+1) and 4-chloro-7,8-dihydro-5H-pyrido[4,3-a]pyrimidine-6,7-dicarboxylic acid 6-tert-butyl ester 7-ethyl ester MS (ESI) m/z 342.1 (M+1) are isolated as an almost 4:1 ratio.

Provenance & Evidence