反应详情

In 3 ml of dichloromethane were dissolved 85 mg of the Compound (1) obtained in Example 1 and 41 mg of 1-hydroxybenzotriazole (HOBT). To the solution was added 62 mg of DCC, and the mixture was stirred at room temperature for 30 minutes, to which was added 60 mg of (4R)-4-benzyloxycarbonylamino-3-isoxazolidinone, prepared by the method described in Journal of Medicinal Chemistry, 13 1013 (1970), followed by stirring at room temperature for 30 minutes. The insolubles which separated out were filtered off and washed with dichloromethane. The filtrate and the washing were combined and concentrated. The concentrate was dissolved in ethyl acetate. The solution was washed with an aqueous solution of sodium hydrogen carbonate and a saturated saline, successively, which was then dried (Na2SO4). The solvent was evaporated off under reduced pressure, and the residue was subjected to a silica gel column chromatography, followed by elution with hexane-ethyl acetate (1:1) to give 96 mg of the subject compound (8) as colorless foamy substance.

1. customprepared by the method
2. stirringby stirring at room temperature for 30 minutes
3. customThe insolubles which separated out
4. filtrationwere filtered off
5. washwashed with dichloromethane
6. concentrationconcentrated
7. dissolutionThe concentrate was dissolved in ethyl acetate
8. washThe solution was washed with an aqueous solution of sodium hydrogen carbonate
9. dry with materiala saturated saline, successively, which was then dried (Na2SO4)
10. customThe solvent was evaporated off under reduced pressure
11. washfollowed by elution with hexane-ethyl acetate (1:1)