METHOD FOR PREPARING S-Bz-MAG3 AS A PRECURSOR OF CONTRAST MEDIA

The present invention provides a method for preparing S-Bz-MAG3 as a precursor of contrast media. Thioglycolic acid and benzoyl chloride are taken for the thiol protection reaction. Next, N,N′-dicyclohexylcarbodiimide and N-hydroxysuccinimide are converted to corresponding ester compounds. The corresponding ester compounds then react with triglycine by amide bonding reaction. The product of the reaction is recrystallized using acetone, filtered, and finally flushed using flushing agent to give the final product. This is a bifunctional chelator and can be bridged with 99mTc and 186/188Re effectively and applied to nuclear medicine imaging and tumor radiotherapy. By taking advantage of fewer synthesis steps and ease of operations, complicated separation and purification reactions can be reduced and thus achieving highly productivity of S-Bz-MAG3.