反应详情

To a solution of benzyl 2-[3-phenoxyacetamido-4-(2,2,2-trichloroethoxycarbonylthio)-2-oxo-1-azetidinyl]-2-formamidoacetate (2.70 g.) and 2,6-lutidine (11.4 ml.) in methylene chloride (16 ml.) was added dropwise phosphorus oxychloride (1.12 ml.) at 0° C. After stirring at the same temperature for 4.8 hours, the mixture was diluted with a mixture of benzene and ethyl acetate (120 ml.) (6:4 by volume), and washed successively with a chilled dilute aqueous solution of sodium chloride, a mixture of 10% phosphoric acid (75 ml.) and a saturated aqueous solution of sodium chloride, a dilute aqueous solution of sodium chloride, ice-water and a saturated aqueous solution of sodium chloride. Drying over magnesium sulfate and removal of the solvent left an oil (2.5 g.), which was chromatographed on silica gel (30 g.) with a mixed solvent of benzene and ethyl acetate (5:1 by volume) as an eluent to give an amorphous solid of benzyl 2-[3-phenoxyacetamido-4-(2,2,2-trichloroethoxycarbonylthio)-2-oxo-1 -azetidinyl]-2-isocyanoacetate.

1. washwashed successively with a chilled dilute aqueous solution of sodium chloride
2. additiona mixture of 10% phosphoric acid (75 ml.)
3. dry with materialDrying over magnesium sulfate and removal of the solvent
4. waitleft an oil (2.5 g.), which
5. customwas chromatographed on silica gel (30 g.) with a mixed solvent of benzene and ethyl acetate (5:1 by volume) as an eluent