Acetyl chloride → HCID 13175939, compound

Participants

Reaction Steps

A solution of acetyl chloride (1.51 cc) in dry tetrahydrofuran (10 cc) is added dropwise, in 5 minutes, to a solution, cooled to 0° C., of 3-(2-aminothiazol-5-yl)-2-benzhydryloxycarbonyl-7-t-butoxycarbonylamino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene (10 g) in dry tetrahydrofuran (150 cc), and a solution of triethylamine (2.8 cc) in dry tetrahydrofuran (5 cc) is then added. The reaction mixture is stirred for 1 hour 30 minutes at about 0°-5° C. and is then treated with further acetyl chloride (1.51 cc) in tetrahydrofuran (10 cc). After 1 hour 50 minutes at 5° C., the reaction mixture is filtered and the filtrate is concentrated to 50 cc and diluted with ethyl acetate (250 cc). The organic phase is washed with a saturated sodium bicarbonate solution (100 cc), with distilled water (100 cc) and with a half-saturated sodium chloride solution (100 cc) and is then dried over magnesium sulphate and concentrated to dryness. Crude 3-(2-acetylamino-thiazol-5-yl)-2-benzhydryloxycarbonyl-7-t-butoxycarbonylamino-8-oxo-5-thia-1-azabicylo[4.2.0]oct-2-ene (10 g) is obtained in the form of a brown froth. Crystallisation from acetonitrile (25 cc) gives pure 3-(2-acetylamino-thiazol-5-yl)-2-benzhydryloxycarbonyl-7-t-butoxycarbonylamino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene (5.9 g) in the form of a whitish crystalline powder whose characteristics are identical to those of the product obtained in variant (A).

Provenance & Evidence