反应详情

2-Thioxo-2,3-dihydrobenzo[d]oxazole-6-carboxylic acid (Example 92B, 394 mg, 2.02 mmol), dimethylamine hydrochloride (181 mg, 2.22 mmol), and O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (844 mg, 2.22 mmol) were combined in tetrahydrofuran (20 mL) and dimethylformamide (2 mL). Diisopropylethylamine (1.5 mL, 8.68 mmol) was added and the mixture was stirred at ambient temperature overnight. The mixture was diluted with dichloromethane, washed with a 1 N aqueous solution of hydrochloric acid, and absorbed on silica gel. The crude mixture was purified with silica gel chromatography eluting with a gradient of methanol in dichloromethane (2-20%) to afford the title compound. MS (ESI+) m/z 222.9 (M+H)+.

1. washwashed with a 1 N aqueous solution of hydrochloric acid
2. customabsorbed on silica gel
3. customThe crude mixture was purified with silica gel chromatography
4. washeluting with a gradient of methanol in dichloromethane (2-20%)