反应详情

In 40 ml of acetonitrile is dissolved 650 mg of (3S,4S)3-(tert-butoxycarbonylamino)-4-carbamoyloxymethyl-1-hydroxy-2-azetidinone, and 0.39 ml of triethylamine and 712 mg of p-nitrobenzyl bromoacetate are added to the solution under ice-cooling with stirring. The reaction solution is stirred at room temperature (15°-25° C.) for 3.5 hours. The solvent is distilled off under reduced pressure, and 50 ml of a mixed solution (1:1) of ethyl acetate and tetrahydrofuran and 50 ml of water are added to the residue. The organic layer is separated, washed with aqueous sodium chloride solution, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The remaining crystals are treated with 15 ml of a mixed solution (1:2) of ether and hexane and filtered to give 98 mg (88.6%) of the above-identified comoound as crystals, m.p. 189°-191° C.

1. additionare added to the solution under ice-
2. temperaturecooling
3. stirringThe reaction solution is stirred at room temperature (15°-25° C.) for 3.5 hours
4. distillationThe solvent is distilled off under reduced pressure, and 50 ml of a mixed solution (1:1) of ethyl acetate and tetrahydrofuran and 50 ml of water
5. additionare added to the residue
6. customThe organic layer is separated
7. washwashed with aqueous sodium chloride solution
8. dry with materialdried over anhydrous magnesium sulfate
9. concentrationconcentrated under reduced pressure
10. additionThe remaining crystals are treated with 15 ml of a mixed solution (1:2) of ether and hexane
11. filtrationfiltered
12. customto give 98 mg (88.6%) of the above-identified comoound as crystals, m.p. 189°-191° C.