[Synthesis of carbon-14 labeled 1-[bis(4-fluorophenyl)methyl]-4-(2,3,4-trimethoxybenzyl)piperazine dihydrochloride (14C-KB-2796)].
Benzyl-14C-1-[bis(4-fluorophenyl)methyl]-4-(2,3,4-trimethoxybenzyl) piperazine dihydrochloride (14C-KB-2796), a new cerebral vasodilator, was synthesized in order to investigate the metabolic fate. The synthesis of carboxy-14C-2,3,4-trimethoxybenzoic acid (IV) was accomplished by the reaction of 2,3,4-trimethoxybromobenzene (II) with ter-butyllithium followed by carboxylation with 14C-carbon dioxide generated from 14C-barium carbonate. Formyl-14C-2,3,4-trimethoxybenzaldehyde (VI) was prepared by the reduction of the methyl ester of IV. The free base of 14C-KB-2796 was obtained by the condensation of VI with bis(4-fluorophenyl)methyl-piperazine, and converted to I. An overall radiochemical yield from 14C-barium carbonate was 39%, the specific activity was 1,816.7 MBq/mmol (49.1 mCi/mmol) and its radiochemical purity was 99% in reverse isotope dilution analysis and thin layer chromatographic method.
Satomi
O
O
Pharmaceuticals Research Center, Kanebo, Ltd., Osaka.
Kawashima
T
T
Awata
N
N
D002250:Carbon Radioisotopes; D002560:Cerebrovascular Circulation; D007553:Isotope Labeling; D010879:Piperazines / Q000138:chemical synthesis*; D014665:Vasodilator Agents / Q000138:chemical synthesis*
D002250:Carbon Radioisotopes; D010879:Piperazines; D014665:Vasodilator Agents; C052424:lomerizine