反应详情

To a solution of 4-chloropyrido[2,3-d]pyrimidine (0.72 g, 4.4 mmol) and 1-Boc piperazine (0.84 g, 4.5 mmol) in DCE (10 mL) and IPA (10 mL) was added triethylamine (4 mL). The mixture was refluxed for 4 hours. After cooling, the solvent was removed. The residue was subject to column chromatography by ethyl acetate to give 4-pyrido[2,3-d]pyrimidin-4-yl-piperazine-1-carboxylic acid tert-butyl ester (1.26 g, 92%). 1H NMR (CDCl3, 400 MHz) δ 9.07 (dd, J=4.30 Hz, J=1.98 Hz, 1H), 8.88 (s, 1H), 8.25 (dd, J=7.99 Hz, J=1.98 Hz, 1H), 7.41 (dd, J=8.18 Hz, J=3.74 Hz, 1H), 3.82 (m, 4H), 3.65 (m, 4H), 1.50 (s, 9H). MS (APCI+) [M+H]+316.

1. temperatureThe mixture was refluxed for 4 hours
2. temperatureAfter cooling
3. customthe solvent was removed