C-11 labelling of AG957 - a potential tyrphostin radiotracer for PET

Abstract

Carbon-11 labelled 4-(N-2,5-dihydroxybenzyl)amino methyl benzoate (AG957), a potential radiotracer for imaging bcr-abl receptors was synthesized. [11C]AG957 was prepared by labelling 4-aminobenzoic acid using [11C]CH3I, which affords the corresponding [11C] methyl ester in excellent yields. Subsequent condensation of the amino group with 2,5-dihydroxy-benzaldehyde formed the respective Schiff base. Reduction of this compound with NaBH3CN gave [11C]AG957 in overall decay corrected radiochemical yield of 65-75% (based on 11CH3I) with an average specific radioactivity of 40 Bq/μmol (1.1 Ci/μmol). The total synthesis time from EOB including formulation was 45 min. At physiological pH, the compou..