反应详情

Under argon and at −78° C., 20.9 ml (20.9 mmol) of lithium aluminium hydride (1 N solution in diethyl ether) were added to 6.8 g (32.17 mmol, purity about 90%) of 2-amino-3-(benzyloxy)-2-methylpropionitrile Example 262A in 329 ml of dry THF. The reaction solution was at −78° C. for 1 h, at −20° C. for 2 h and at 0° C. for 2 h. 3.22 ml of water, 3.22 ml of 2 N aqueous sodium hydroxide solution and 6.44 ml of water were then added carefully. The precipitate was filtered off and washed with THF and methanol, and the filtrate was concentrated. This gave 8 g of the crude product. 7 g of this crude product were purified by silica gel chromatography (mobile phase: dichloromethane/2 N ammonia in methanol=from 20/1 to 10/1). This gave 1.52 g of the target compound (about 28% of theory).

1. filtrationThe precipitate was filtered off
2. washwashed with THF and methanol
3. concentrationthe filtrate was concentrated
4. custom7 g of this crude product were purified by silica gel chromatography (mobile phase: dichloromethane/2 N ammonia in methanol=from 20/1 to 10/1)