CEPHALOSPORIN DERIVATIVES AND PROCESS FOR THEIR PREPARATION

摘要

A process is disclosed for producing an imidazole carboxylic acid derivative of the following general formula in the form of one or more sodium salt:-

wherein each of X and R, which may be the same or different, is a hydrogen atom or a substituent; which process comprises reacting, in an aqueous solution of sodium iodide, 4-pyridineethanesulphonic acid and a compound of the following general formula:-

wherein X and R are as defined above.
With the process for the present invention it ispossible to separate from the reaction solution the sodium salt(s) of the compound of formula 1 in a manner considerably easier that the production of sodium salts from other salts of the compound of formula 1 as previously disclosed. Moreover the sodium salts are less toxic than the corresponding potassium salts.