Trifluoroacetic acid → HCID 136980668, compound

Participants

Reaction Steps

To 7-cyclopropyl-3-(2-trimethylsilylethoxymethyl)pyrido[4,3-d]pyrimidin-4-one (6, 2.0 g, 6.3 mmol) in dichloromethane (10 mL) at 0° C. was added a 20% trifluoroacteic acid solution in dichloromethane (10 mL, 6.3 mmol). The reaction mixture was warmed to room temperature and stirred for 3 h. After complete deprotection as indicated by TLC the reaction mixture was concentrated, taken up in dichloromethane and concentrated. This process was repeated 2-3 times. Tetrahydrofuran (20 mL) was added to the crude residue and cooled to 0° C. 3 M potassium hydroxide solution (10 mL, 6.3 mmol) was added to the solution bringing the pH to 9-10. The suspension was stirred for 6-7 h. The reaction was concentrated, the residue was diluted with 10% methanol in dichloromethane and the organic layers were washed with 10 mL water and 10 mL of a saturated brine solution. The organic layers were separated, dried over magnesium sulfate, filtered and concentration to dryness to afford 7-cyclopropyl-3H-pyrido[4,3-d]pyrimidin-4-one (7) as a brown solid. Yield: 1.00 g, 85%; MS (ESI) m/z 188.18 [M+1]+; 1H NMR (400 MHz, DMSO-d6) δ 12.57 (bs, 1H), 9.15 (s, 1H), 8.32 (s, 1H), 7.38 (s, 1H), 2.27 (bs, 1H), 1.03 (bs, 4H).

Provenance & Evidence