METHOD OF PRODUCING HIGH-PURITY DIALKYL PEMETREXED Russian patent published in 2015 - IPC C07D487/04 

FIELD: chemistry.

SUBSTANCE: invention describes a method of producing and a method of purifying dialkyl pemetrexed of formula (I) , having antifolate action. The compound can be used to treat non-small-cell cancer and, coupled with cisplatin, to treat malignant pleural mesothelioma of the lungs. The method includes reacting a carboxylic acid of formula (II) with a diester of glutamic acid of formula (III) or an acid-addition salt thereof. The process is carried out in the presence of a substituted triphenyl phosphate of formula (IV) , a base and a solvent. In formulae (I) and (III) each R1 and R2 independently represents alkyl groups. In formula (IV) X, Y and Z assume values given in the claim.

EFFECT: use of safe, mild, cheap, non-oxidising and easy to handle triphenyl phosphate simplifies the process and enables to obtain, for example, diethyl pemetrexed with purity higher than 99%.

14 cl, 12 ex