(Z)-2-(2-Tritylaminothiazol-4-yl)-2-methoxyiminoacetic acid → HCID 53839652, compound

Participants

Reaction Steps

A solution of 2-(2-tritylamino-thiazol-4-yl)-2-methoxyimino-acetic acid (syn isomer) (7.2 g) in methylene chloride (22.4 cc) is added, in a single shot, to a solution of 7-amino-2-benzhydryloxycarbonyl-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene (3.15 g) in methylene chloride (31.5 cc). The temperature rises from 8° to 14° C. The mixture is kept stirred for one hour 15 minutes, during which the temperature rises to 20° C., and is then washed with 0.5 N hydrochloric acid (10 cc), distilled water (10 cc) and a saturated sodium bicarbonate solution (20 cc). The insoluble matter formed is filtered off, and the organic phase is washed again with distilled water (2×20 cc), dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (20 mm Hg) at 40° C. The residue is chromatographed on a column (diameter: 3 cm, height: 33 cm) containing silica gel (125 g), elution being carried out with a 20:80 (by volume) mixture of ethyl acetate and cyclohexane (1.2 liters) and then with a 40:60 (by volume) mixture (1 liter), and 50 cc fractions of eluate being collected. Fractions 31 to 44 are evaporated and 2-benzhydryloxycarbonyl-7-[2-methoxyimino-2-(2-tritylamino-thiazol-4yl)-acetamido]-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene, syn isomer (2.8 g) is obtained in the form of a pale yellow solid.

Provenance & Evidence