| 摘要 |
<p>The present invention provides a process for the preparation of 9-O-methylclavulanic acid or a pharmaceutically acceptable salt or in-vivo hydrolysable ester thereof which process comprises the reaction of a cleavable ester of clavulanic acid with methyl iodide or methyl bromide in dry inert organic solvent in the presence of silver ions and either molecular sieve or calcium sulphate and subsequently: i) converting any cleavable ester group which is not in-vivo hydrolysable into a free acid, a pharmaceutically acceptable salt or in-vivo hydrolysable ester group; ii) optionally converting any cleavable ester group which is in-vivo hydrolysable into a free acid, a pharmaceutically acceptable salt or a different in-vivo hydrolysable ester group.</p> |
