Hydrochloric Acid → Cephalosporanic Acid

Participants

Reaction Steps

Solutions A and B are produced according to a method as described in Example 2, but using in solution A 18.57 g of 7-aminocephalosporanic acid instead of 18.57 g of 7-amino-3-{[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl)thio]methyl}-3-cephem-4-carboxylic acid. While stirring the mixture obtained is poured onto an ice-cooled suspension of potassium bicarbonate in a mixture of water and 2-propanol. The pH of the two-phase system obtained is adjusted to 2.0 with 2 N HCl. The organic phase is separated off and treated with 7.5 ml of water and 3.81 g thiourea while stirring. The pH of the mixture is kept between 3.0 and 3.5 by addition of a solution of 2-amino-2,4,4-trimethylpentane in dichloromethane. A precipitate is obtained. 2-Propanol is added to the suspension obtained while stirring and the precipitate is isolated and dried. 7-[2-(Aminothiazol-4-yl)-2(Z)-methoximino)acetamido]-3-acetoxymethyl-3-cephem-4-carboxylic acid is obtained.

Provenance & Evidence