Process for preparation of the (6-S) optically active form of folic acid obtained by synthesis

摘要

Process for the preparation of the (6-S) enantiomer of folic acid characterised in that it comprises preparing a salt of the (6 - R, S) racemate of folic acid or the intermediate used in the synthesis of folic acid comprising the (6-R, S) racemate of 5-N-formyl-5,6,7,8- tetrahydropteroic acid with an optically active amine selected from S-(-)-(α)-methyl-p-nitrobenzylamine or (S)-(-)-α-phenyl ethylamine and subsequent crystallisation of the salt containing the (6-S) optically active form of folic acid or the 5-N-formyl- 5,6,7,8-tetrahydropteroic intermediate.