Chloroacetyl chloride → 2-Benzhydryloxycarbonyl-7-t-butoxycarbonylamino-3-(2-chloroacetamido-thiazol-5-yl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene

Participants

Reaction Conditions

Reaction Steps

Chloroacetyl chloride (12.37 g) is added to a solution of 3-(2-amino-thiazol-5-yl)-2-benzhydryloxycarbonyl-7-t-butoxycarbonylamino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene (60 g) in tetrahydrofuran (350 cc) cooled to 0° C., and triethylamine (16.3 cc) is then added in 6 minutes. After 1 hour at 0° C., the reaction mixture is diluted with a half-saturated sodium bicarbonate solution (800 cc) and extracted with ethyl acetate (3×200 cc). The combined organic phases are washed with a saturated sodium chloride solution (250 cc) and dried, after which they are concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 40° C. to give an orange froth (78 g) which is recrystallised from acetonitrile (300 cc) to give cream crystals (37.4 g) of 2-benzhydryloxycarbonyl-7-t-butoxycarbonylamino-3-(2-chloroacetamido-thiazol-5-yl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene

Provenance & Evidence