反应详情

2-Thioxo-2,3-dihydrobenzo[d]oxazole-6-carboxylic acid (Example 92B, 424 mg, 2.17 mmol), ethanamine hydrochloride (266 mg, 3.26 mmol), and O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (991 mg, 2.61 mmol) were combined in tetrahydrofuran (5 mL). Triethylamine (1.4 mL, 977 mmol) was added and the mixture was stirred at room temperature overnight. The reaction 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%). The chromatographed material was triturated with dichloromethane to afford the title compound. MS (ESI−) m/z 220.9 (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%)
5. customThe chromatographed material was triturated with dichloromethane