反应详情

To a cooled solution of 7-(1-benzyloxycarbonyl-1-azidomethyl)-3-phenoxymethyl-6-oxo-2-thia-4,7-diazabicyclo[3,2,0]hept-3-ene (3.0 g.) in tetrahydrofuran (48 ml.) was added silver tetrafluoroborate (2.05 g.), followed by a solution of p-toluenesulfonic acid (145.8 mg.) in water (8.1 ml.). After the resultant mixture was stirred at 0° C. for 9 hours, it was concentrated to a volume of 10 ml. To the concentrate was added a mixture of methanol (5 ml.) and water (10 ml.) and precipitates were triturated, filtered and washed with water (three times), a mixture of methanol (5 ml.) and water (10 ml.) (several times), methanol, diethyl ether and hexane, successively to give silver salt at the mercapto group of benzyl 2-azido-2-(3-phenoxyacetamido-4-mercapto-2-oxo-1-azetidinyl)acetate (3.75 g.).

1. concentrationit was concentrated to a volume of 10 ml
2. additionTo the concentrate was added
3. additiona mixture of methanol (5 ml.) and water (10 ml.)
4. customprecipitates
5. customwere triturated
6. filtrationfiltered
7. washwashed with water (three times)
8. additiona mixture of methanol (5 ml.) and water (10 ml.) (several times), methanol, diethyl ether and hexane