Process for producing folic acid derivatives

摘要

This invention provides a process for efficient production of folic acid derivatives suitable for forming conjugates of anticancer drug with folic acid. It discloses a process comprising a step of reacting 2-amino-protected pteroylimidazole with gamma-lower alkyl glutamate; and a step of reacting the resulting product with an amino compound having a reactive group which is readily reactable with a functional group of the drug.