反应详情

t-Butyl 4-[trans-4-(methoxycarbonyl)cyclohexyl]-3-oxopiperazine-1-carboxylate (385 mg) obtained in Reference Example 71 (3) is dissolved in methanol (8 ml), and thereto is added 1 N aqueous sodium hydroxide solution (3.4 ml) under ice-cooling. The reaction solution is stirred at room temperature for 20 hours and concentrated under reduced pressure. Water and chloroform are poured to the residue, and aqueous layer is acidified by addition of 2 N hydrochloric acid. The organic layer is separated, washed with saturated brine and dried over sodium sulfate. The solvent is removed by evaporation under reduced pressure to give the title compound (375 mg).

1. temperaturecooling
2. concentrationconcentrated under reduced pressure
3. additionWater and chloroform are poured to the residue, and aqueous layer
4. additionis acidified by addition of 2 N hydrochloric acid
5. customThe organic layer is separated
6. washwashed with saturated brine
7. dry with materialdried over sodium sulfate
8. customThe solvent is removed by evaporation under reduced pressure