Potassium Carbonate → benzhydryl (6R,7R)-7-[[(2Z)-2-[4,5-bis[(2-chloroacetyl)oxy]-2-methylbenzoyl]oxyimino-2-[2-(tritylamino)-1,3-thiazol-4-yl]acetyl]amino]-3-[(7-methyl-5-oxo-[1,3,4]thiadiazolo[3,2-a]pyrimidin-2-yl)sulfanylmethyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Steps

To an ice-cooled solution of the product obtained in Step 4 (0.6 g) in dry dichloromethane (15 ml) was added potassium carbonate (0.1 g) at once, followed by dropwise addition of a solution of 4,5-bis(chloroacetoxy)-2-methylbenzoyl chloride (0.25 g) in dry dichloromethane (10 ml). The mixture was stirred under ice cooling for one hour and then at room temperature for an additional two hours. After filtering off the insoluble matters, the filtrate was washed with water and with brine, and dried over anhydrous sodium sulfate. The dried solution was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography, giving 0.47 g of the objective compound.

Provenance & Evidence