Dacthal → 7-amino-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid hydrochloride

Participants

Reaction Conditions

Reaction Steps

A 11 ml portion of acetonitrile was added to 2.72 g of 7-ACA and 1.28 g of 5-mercapto-1-methyl-1H-tetrazole, and 14.9 g of DCPA was added through a dropping funnel to the mixture with stirring and under cooling at -25° to -20° C., followed by rinsing the funnel with 1 ml of acetonitrile. The reaction mixture was warmed to 15° C., stirred at 14° to 16° C. for 40 minutes and cooled to -30° C., followed by adding dropwise 40 ml of ethanol at -30° to -20° C. The resultant solution was warmed to room temperature, and stirred under ice-cooling for 3.0 hours after the addition of 300 ml of methylene chloride, 100 ml of ether and 70 ml of ether saturated with water. The crystals separated out were recovered by filtration, washed with ether and dried, thereby affording 3.77 g (86.0% of purity as determined by high performance liquid chromatography, 88.9% of yield) of 7-amino-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid hydrochloride.

Provenance & Evidence