Ammonia → 7-Amino-3-methoxymethyl-3-cephem-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

8.94 g of a methanolic solution of methoxysulfonic acid (prepared as described in Preparation 2) and 2.10 g of trimethyl borate were added to 15 ml of sulfolane. The mixture was cooled to 20° C. 2.74 g of 7-ACA were added to the mixture and the mixture was stirred for 1.5 hours at 20° C. The progress of the reaction was examined by high performance liquid chromatography (HPLC). After completion of the reaction, the reaction mixture was poured over crushed ice and the pH was adjusted to 3.5 by addition of aqueous ammonia. The crystals precipitated were filtered off, washed with water and dried to afford 2.84 g of crude 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid. After this, the crude crystals were dissolved in aqueous ammonia in order to adjust the pH to 7. This solution was then applied to an adsorption column (polystyrene type high porous polymer) and the pH of the effluent was adjusted to 3.5 using hydrochloric acid. The crystals precipitated were filtered off, washed with water and dried to give 2.14 g (yield 87%) of the title compound at a high purity.

Provenance & Evidence