Patent ID: 11925644
Assignee: MERCK PATENT GMBH
Field: Pharmaceuticals (Chemistry)
Classification: CPC A  C | IPC A  C

Claim 3:
4. A process for obtaining the crystalline salt comprising 5-methyl-(6S)-tetrahydrofolic acid and L-leucine ethyl ester according to claim 1 comprising the steps of:
i) providing a mixture of 5-methyl-(6S)-tetrahydrofolic acid and L-leucine ethyl ester, in water as a solvent;
ii) adding sodium as a base, optionally in water as a solvent, to dissolve the compounds;
iii) heating the composition to at least 60° C. and optionally carrying out a clear filtration;
iv) crystallizing and cooling the mixture to a temperature between 1° C. and 30° C., optionally adding more water as a solvent; and
v) isolating the obtained solid material and optionally drying the product.