反应详情

0.21 g of sodium borohydride was added to a solution of 1.98 g of N-[4-(4-piperidinomethyl-2-pyridyloxy)-cis-2-butenyl]-5-(methoxycarbonylmethylthio)pentanamide [prepared as described in step (b) above] in 40 ml of tetrahydrofuran, and 8 ml of methanol were added dropwise to the mixture, whilst ice-cooling; it was then stirred at room temperature for 3 hours. At the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure, and the residue was mixed with water. The resulting aqueous mixture was extracted with ethyl acetate, and the extract was freed from the solvent by distillation under reduced pressure. The residue was purified by column chromatography through silica gel, using a 1:9 by volume mixture of methanol and methylene chloride as the eluent, to give 1.51 g (yield 63%) of the title compound as an oil.

1. additionwere added dropwise to the mixture, whilst ice-
2. temperaturecooling
3. concentrationAt the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure
4. additionthe residue was mixed with water
5. extractionThe resulting aqueous mixture was extracted with ethyl acetate
6. distillationthe extract was freed from the solvent by distillation under reduced pressure
7. customThe residue was purified by column chromatography through silica gel
8. additionby volume mixture of methanol and methylene chloride as the eluent