Water → HCID 53791026, compound

Participants

Reaction Conditions

Reaction Steps

p-Toluenesulphonyl chloride (1.31 g) is added to a solution, cooled to 5° C., of the syn isomer of 2-benzhydryloxycarbonyl-7-{2-[(2-t-butoxycarbonylprop-2-yl)-oxyimino]-2-(2-tritylaminothiazol-4-yl)-acetamido}-3-formylmethyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene (product 5e) (4.45 g) in pyridine (50 cc). The temperature is left to rise to 20° C. in the course of 30 minutes, the mixture is stirred for 1 hour at 20° C. and poured into iced water (300 cc), the water is decanted and the insoluble pasty product is taken up in ethyl acetate (300 cc). The solution is washed with 1 N hydrochloric acid (100 cc), a saturated solution of sodium bicarbonate (100 cc) and a saturated solution of sodium chloride (100 cc), dried over sodium sulphate and filtered and the filtrate is concentrated to dryness at 20° C. under 20 mm Hg (2.7 kPa). The product thus obtained is used as such for the remainder of the synthesis. This product (1 g) is purified by chromatography on a column of silica gel (0.05-0.2) (20 g) (diameter of the column: 1.7 cm), elution being carried out with an 80/20 (by volume) mixture of cyclohexane and ethyl acetate, and 50 cc fractions being collected. Fractions 4 to 12, containing the pure product, are evaporated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. to give a product (5d) (0.43 g), which is a mixture of the E and Z forms (in proportions--determined by NMR--of 75% of the E form and 25% of the Z form), in the form of a pale yellow solid.

Provenance & Evidence