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

Participants

Reaction Conditions

Reaction Steps

22.0 g of a methanolic solution of methoxysulfonic acid (prepared as described in Preparation 3) and 2.10 g of trimethyl borate were added to 30 ml of dimethyl carbonate. The mixture was cooled to 10° C. Next, 2.74 g of 7-ACA were added and the mixture was stirred at 10° C. for 1.5 hours. After completion of the reaction, the reaction mixture was poured over crushed ice, and aqueous ammonia was added thereto to adjust the pH to 3.5. The crystals precipitated were filtered off, washed with water and dried to afford 2.80 g of crude 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid. Water was added to the crude crystals, and then aqueous ammonia was added to adjust the pH to 8. The mixture was then decolored using activated carbon. The activated carbon was filtered off and the filtrate was adjusted to pH 3.5 with hydrochloric acid. The crystals precipitated were filtered off, washed with water and dried to give 2.11 g (yield 86%) of the desired compound in a highly pure form.

Provenance & Evidence