Process for the preparation of leucovorin and calcium leucovorin

摘要

Leucovorin is prepared from anhydroleucovorin or one of its salts by using an amine base to open the ring of anhydroleucovorin or of one of its salts. After the addition of a quantity of a water-soluble calcium salt which is at least equimolar to the anhydroleucovorin, the calcium leucovorin is isolated. The resulting calcium leucovorin no longer has to be purified by column chromatography.