THE SYNTHESIS OF N-ACETYL-4-S-CYSTEAMINYL [U-C-14]PHENOL AS A BASIS FOR THE DEVELOPMENT OF AN ANTIMELANOMA AND MELANOMA-RADIOIMAGING AGENT

This study reports the synthesis of C-14-labelled N-acetyl-4-S-cysteam inylphenol ([C-14]N-Ac-4-S-CAP), a potent melanocytotoxic and anti-mel anoma agent. A reaction of [U-C-14]phenol with NH2CH2CH2S+ cation in H Br solution was used for the synthesis of (4-S-cysteaminyl[C-14]phenol [C-14]4-S-CAP). The excess cystamine was removed, and [C-14]4-S-CAP an d 2-S-cysteaminyl[C-14]phenol ([C-14]2-S-CAP) were separated on prepar ative thin layer chromatography. [C-14]4-S-CAP was acetylated with ace tic anhydride in pyridine and subsequently O-deacetylated with NH3 in methanol, resulting [C-14]N-Ac-4-S-CAP (3.8% radiochemical yield; a sp . act. of 450 kBq/mumol; radiochemical purity >99%).