Dichloromethane → (6R,7R)-7-amino-3-[[[5-(hydroxycarbamoyl)-2-methyl-s-triazolo[1,5-a]pyrimidin-7-yl]thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Participants

Reaction Steps

N-Hydroxy-7-mercapto-2-methyl-s-triazolo[1,5-a]pyrimidine-5-carboxamide (250 mg) (1.1 mmol) and 275 mg (1.0 mmol) of 7-amino-cephalosporanic acid are suspended in 15 ml of sulpholane/dichloromethane (1:1 v/v) and treated at 0° C. with 3.5 ml of boron trifluoride diethyl etherate. The mixture is stirred at 0°-5° C. for 2 hours and at room temperature for 3 hours. Subsequently, 60 ml of dichloromethane are added thereto. Insoluble material is filtered off under suction, dissolved in water and treated with saturated sodium bicarbonate solution until the pH value 3 has been reached. The precipitated product is filtered off under suction and washed in succession with water and diethyl ether. There are obtained 295 mg of (6R,7R)-7-amino-3-[[[5-(hydroxycarbamoyl)-2-methyl-s-triazolo[1,5-a]pyrimidin-7-yl]thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid as a beige powder.

Provenance & Evidence