反应详情

Sodium borohydride (4.4 g, 116 mmol, 1.20 equiv.) was added in several batches to a solution of 1-benzyl-3-methoxycarbonylamino-4-methyl-pyridinium bromide (35 g, 104 mmol, 1.00 equiv.) in methanol (300 mL). The resulting solution was stirred at ambient temperature for about 16 hours, and then water (200 mL) was added. After concentrating the mixture in vacuo, standard extractive workup with ether (3×200 mL) gave a crude residue that was then purified by silica gel column chromatography (dichloromethane/methanol (20:1)) to afford the title product as a yellow solid (18 g; yield=66%). LC-MS: m/z=261 (M+H)+.

1. concentrationAfter concentrating the mixture in vacuo, standard extractive workup with ether (3×200 mL)
2. customgave a crude residue that
3. customwas then purified by silica gel column chromatography (dichloromethane/methanol (20:1))