I. Nakatsuka, K. Kawahara, T. Kamada
1979
Citations
0
Influential Citations
3
Citations
Journal
Journal of Labelled Compounds and Radiopharmaceuticals
Abstract
2′Amino-4′-fluoro-4-[4-hydroxy-4-(3-trifluoromemethylphenyl)-piperidino]butyrophenone (ID-470B)(1), a novel neuroleptic agent, was labelled with carbon-14 at the carbonyl position for use in metabolic studies. The synthesis was achieved according to the reaction scheme shown in Fig. 1. Cyclopropyl 2,4-difluorophenyl ketone-(carbonyl-14C) (2a) was prepared from cyclopropane-carboxylic-14c acid by the Friedel-Crafts reaction with m-difluoro-benzene. Ring-opening of 2a with hydrogen chloride gave 4-chloro-2′,4′-difluorobutyrophenone-1-14c (3a). After ketalization of 3a, the resulted ketal (4) was condensed with the piperidine (5) and subsequently hydrolyzed with hydrochloric acid to give 6. Benzylamination of 6. with benzylamine, followed by debenzylation by catalytic hydrogenolysis gave ID-4708-(carbonyl-14C) (1). The overall radiochemical yield of 1 from barium carbonate-14C was 13%.