反应详情

11.7 g of (2S,4S)-4-(4-methoxybenzylthio)-1-(4-nitrobenzyloxycarbonyl)-2-pyrrolidinecarboxylic acid [prepared as described in step (b) above] were dissolved in 100 ml of anhydrous acetonitrile. 4.9 g of N,N'-carbonyldiimidazole were then added to the solution, which was then stirred for 30 minutes at room temperature. At the end of this time, 3.5 g of N-methylpiperazine were added to the reaction solution, and it was then stirred at room temperature for 30 minutes, and then at 40° C. for 30 minutes. The reaction solution was then condensed to 30 ml by evaporation under reduced pressure, and the residue was diluted with 300 ml of ethyl acetate. The resulting solution was washed once with 100 ml of a saturated aqueous solution of sodium hydrogencarbonate three times with 100 ml of water and once with 100 ml of a saturated aqueous solution of sodium chloride. The ethyl acetate layer was condensed by evaporation under reduced pressure, to obtain 1.36 g of a crystalline residue. Recrystallization of this crystalline residue from 100 ml of ethanol gave 13.0 g of the title compound as colorless needles, melting at 140°-141° C.

1. stirringwas then stirred at room temperature for 30 minutes
2. waitat 40° C. for 30 minutes
3. customcondensed to 30 ml
4. customby evaporation under reduced pressure
5. additionthe residue was diluted with 300 ml of ethyl acetate
6. washThe resulting solution was washed once with 100 ml of a saturated aqueous solution of sodium hydrogencarbonate three times with 100 ml of water and once with 100 ml of a saturated aqueous solution of sodium chloride
7. customcondensed
8. customby evaporation under reduced pressure