The present invention refers to a process for the synthesis of pemetrexed and salts thereof, in particular to a lysine salt thereof, to said salt as such and to pharmaceutical compositions that comprise the same. Furthermore, the present disclosure also relates to a crystalline form of the synthesis intermediate pemetremexed diethyl ether and a crystalline form of the pemetrexed lysine salt.本發明係關於一種合成培美曲塞及其鹽(特定言之,其離胺酸鹽)之方法,亦關於該鹽及包含培美曲塞及其鹽之醫藥組成物。此外,本發明亦係關於合成中間體培美曲塞乙醚之結晶形態及培美曲塞離胺酸鹽之結晶形態。
