m-Chloroperbenzoic acid → 2-Benzhydryloxycarbonyl-7-{2-[(2-t-butoxycarbonylprop-2-yl)-oxyimino]-2-(2-tritylaminothiazol-4-yl)-acetamido}-8-oxo-3-[2-(pyridin-3-yl-amino)-thiazol-5-yl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene 5-oxide

Participants

Reaction Conditions

Reaction Steps

A solution of m-chloroperbenzoic acid (2.59 g) in methylene chloride (52 cc) is run, in the course of 30 minutes, into a solution, cooled to 0° C., of the syn isomer of 2-benzhydryloxycarbonyl-7-{2-[(2-t-butoxycarbonylprop-2-yl)-oxyimino]-2-(2-tritylaminothiazol-4-yl)acetamido}-8-oxo-3-[2-(pyridin-3-yl-amino)-thiazol-5-yl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene (13.46 g) in methylene chloride (123 cc). The mixture is stirred for 15 minutes at 0° C. and the reaction solution is then diluted with methylene chloride (200 cc). The mixture is washed successively with a semi-saturated solution of sodium bicarbonate (200 cc) and distilled water (2×200 cc). The organic phase is then dried over anhydrous magnesium sulphate and filtered and the filtrate is then concentrated under reduced pressure (100 mm Hg; 13.3 kPa) at 30° C. The residue is purified by chromatography on a column (height=29 cm, diameter=5.8 cm) containing silica gel (0.04-0.06 mm), elution being carried out under a pressure of 0.4 bar with a mixture of cyclohexane and ethyl acetate (10/90 by volume) (2 liters) and 125 cc fractions being collected. Fractions 11 to 15 are combined and concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. to give the syn isomer of 2-benzhydryloxycarbonyl-7-{2-[(2-t-butoxycarbonylprop-2-yl)-oxyimino]-2-(2-tritylaminothiazol-4-yl)-acetamido}-8-oxo-3-[2-(pyridin-3-yl-amino)-thiazol-5-yl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene 5-oxide (0.70 g) in the form of a hard yellow foam.

Provenance & Evidence