反应详情

Gaseous methylamine was introduced into a solution of 1.33 g (3.76 mmole) of (3S, 5S)-5-[(1S)-1-(t-butoxycarbonyl)amino-2-cyclohexylethyl]-3-isopropyldihydrofuran-2(3H)-one (prepared as described in Preparation 1) in 10 ml of methanol to ensure saturation, whilst ice-cooling. The reaction vessel was then stoppered tightly and allowed to stand overnight. At the end of this time, the solvent was removed by distillation under reduced pressure and the residue was recrystallized from hexane to afford 1.32 g (yield 91%) of the title compound as white crystals, melting at 154°-157° C.

1. temperaturewhilst ice-cooling
2. customAt the end of this time, the solvent was removed by distillation under reduced pressure
3. customthe residue was recrystallized from hexane