Patent ID: 7674915

Claim:
A method of manufacturing a glutamic acid compound represented by formula (3) below or a salt thereof, comprising: (a) subjecting a 4-protected hydroxy-pyroglutamic acid compound represented by formula (1) below or a salt thereof to an alkylation reaction to obtain a 4-protected hydroxy-4-substituted pyroglutamic acid derivative represented by formula (2) below or a salt thereof; and (b) subjecting said 4-protected hydroxy-4-substituted pyroglutamic acid derivative represented by formula (2) below or salt thereof to hydrolysis and deprotection: where R 1 , R 4 and R 5 each independently of one another represent a group selected from the group consisting of a hydrogen atom and a hydrocarbon group, R 2 represents a protecting group for a hydroxyl group, R 3 represents a group selected from the group consisting of a hydrocarbon group optionally having a substituent and a heterocyclyl hydrocarbon group optionally having a substituent, and P represents a protecting group for an imino group.