Hydrochloric Acid → HCID 13175940, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 2-benzhydryloxycarbonyl-3-(1-bromo-2-oxoethyl)-7-t-butoxycarbonylamino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene (a mixture of the bromoaldehyde epimers) (5.87 g) and thiobenzamide (1.5 g) in dry tetrahydrofuran (60 cc) is stirred at 20° C. for 1 hour 20 minutes, and thereafter there are added to the reaction mixture, cooled to 2° C., methanesulphonyl chloride (0.85 cc) followed, in 5 minutes, by triethylamine (5.6 cc). After having been stirred for 2 hours at 2° C., the reaction mixture is poured into a mixture of ethyl acetate (100 cc) and 1N hydrochloric acid (50 cc). The organic phase is washed with a saturated sodium bicarbonate solution (100 cc) and then with a saturated sodium chloride solution (100 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. The residue is chromatographed on a column (height: 25 cm; diameter: 5 cm) of silica gel (0.04-0.06 mm), elution being carried out under a pressure of 0.4 bar (40 kPa) with an 80:20 (by volume) mixture of cyclohexane and ethyl acetate, and 125 cc fractions being collected. Fractions 17 to 22, containing the pure product, are combined and concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. 2-Benzhydryloxycarbonyl-7-t-butoxycarbonylamino-8-oxo-3-(2-phenyl-thiazol-5-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene (1 g) is obtained in the form of a yellow froth.

Provenance & Evidence