反应详情

A mixture of 4.855 gms. (10 mmol.) of p-nitrobenzyl 6-phenoxyacetamido-2,2-dimethylpenam-3-carboxylate, 16.94 gms. (80 mmol.) of 2,2,2-trichloroethyl chloroformate, 18 ml. of N,O-(bis-trimethylsilyl)trifluoromethylacetamide, and 20 ml. of methylene chloride was prepared. The mixture was permitted to stand at room temperature overnight. The mixture then was heated at reflux for 7 hours after which it was again permitted to stand at room temperature overnight. Heating then was continued for an additional 6 hours. The mixture then was evaporated to a residue, and the residue was dissolved in benzene which then was added to a large excess of heptane. The resulting insoluble material was filtered off, dissolved in benzene, and chromatographed over silica gel using a benzene-ethyl acetate elution gradient. p-Nitrobenzyl 6-[N-(phenoxyacetyl)-N-(2,2,2-trichloroethoxycarbonyl)amino]-2,2-dimethylpenam-3-carboxylate (4.76 gms.; 72 percent) was obtained as product.

1. additionA mixture of 4.855 gms
2. temperatureThe mixture then was heated
3. temperatureat reflux for 7 hours after which it
4. waitto stand at room temperature overnight
5. temperatureHeating
6. waitthen was continued for an additional 6 hours
7. customThe mixture then was evaporated to a residue
8. dissolutionthe residue was dissolved in benzene which
9. additionthen was added to a large excess of heptane
10. filtrationThe resulting insoluble material was filtered off
11. dissolutiondissolved in benzene
12. customchromatographed over silica gel using
13. washa benzene-ethyl acetate elution gradient