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

Participants

Reaction Conditions

Reaction Steps

A solution of the anhydride of 2-(2-tritylaminothiazol-4-yl)-2-methoxyimino-acetic acid (syn isomer)(7.2 g) in methylene chloride (22.5 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 returns 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 (two×20 cc), dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (20 mm Hg) at 40° C. The residue is chromatographed over a column (diameter: 3 cm, height: 33 cm) containing silica gel (125 g), and elution is carried out with ethyl acetate/cyclohexane mixtures (1.2 and 1 liter, of respective composition 20:80 and 40:60 by volume), 50 cc fractions of eluate being collected. Fractions 31 to 44 are evaporated and 2-benzhydryloxycarbonyl-3-methyl-8-oxo-7-[2-methoxyimino-2-(2-tritylamino-thiazol-4-yl)-acetamido]-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