Chloroform → HCID 70635581, compound

Participants

Reaction Conditions

Reaction Steps

To a cooled (5° C.) stirred solution of benzhydryl 7-(2-thienylacetamido)-3-(2-bromoethoxycarbonyl)-2-cephem-4-carboxylate (0.29 g., 0.453 mmol.) in 30 ml. chloroform was added 85% m-chloroperbenzoic acid (0.101 g., 497 mmol.) in 3 ml. chloroform. The mixture was allowed to stir with cooling for 30 minutes, and then was washed with sodium bicarbonate solution (2X) and sodium chloride solution and dried over Na2SO4. Evaporation in vacuo gave 301 mg. of the Δ3 sulfoxide. The sulfoxide was dissolved in 25 ml. dimethylformamide, cooled briefly, and then treated with 0.06 ml. (0.678 mmol., 1.5 eq.) phosphorous trichloride. The mixture was allowed to stir at ambient temperature for 30 minutes. Ethyl acetate was added to the reaction mixture, and then it was washed successively with water (2X), aqueous sodium bicarbonate (2X), and brine. The organic layer was dried over anhydrous Na2SO4 and evaporated in vacuo to dryness. The crude product was chromatographed on 5 g. of silica gel using a benzene-ethyl acetate gradient providing benzhydryl 7-(2-thienylacetamido)-3-(2-bromoethoxycarbonyl)-3-cephem-4-carboxylate (0.154 g., 53%) as a colorless solid: ir (CHCl3) 1799 cm-1 (β-lactam C = 0); nmr (DMSO-d6) 3.34 (m, 2, CH2Br), 3.76 (s, 2, side chain CH2), 3.8-4.4 (m), 5.20 (d, 1, J = 5.0 Hz, C6 --H) and 5.86 ppm (q, 1, J = 5.0 and 9.0 Hz, C7 --H).

Provenance & Evidence