NOVEL PROCESS FOR THE SYNTHESIS OF PEMETREXED DISODIUM SALT

摘要

The present invention relates to a novel process for the preparation of pemetrexed diethyl ester 2 by purifying the mixture obtainable by reacting compounds 1 and 1a in the presence of a chemical agent capable of promoting the formation of a peptide bond in an aprotic organic solvent characterized in that the mixture is subjected to the following steps: a) washing with a basic aqueous solution; b) concentration of the organic phase; c) addition of a polar organic solvent and/or a mixture of polar organic solvents; d) precipitation of the pemetrexed diethyl ester 2.