Patent ID: 8487126

Claim:
A process for preparation of a diethylenetriaminepentaacetic acid derivative; wherein the diethylenetriaminepentaacetic acid derivative is represented by the following formula (I): wherein R 1 to R 5 are independently C 1-6 alkyl groups; comprising the steps of: reacting a diethylenetriaminepentaacetic acid pentaester represented by the following formula (II) with a halogenated ally compound represented by the following formula (III) in an aprotic solvent: wherein R 1 to R 5 have the same meaning as the above; and “Hal” is a halogen atom; removing the excess halogenated ally compound (III); and reacting a reaction product of the diethylenetriaminepentaacetic acid pentaester (II) and the halogenated ally compound (III) with a base in a solvent.