Synthesis of (R) and (S) 3-aminoquinuclidine-[3-14C] enantiomers, important components of a variety of 5-HT3 ligands
摘要:
3-Aminoquinuclidine, an important fragment associated with many 5-HT (serotonin) receptor ligands, has been synthesized using a C-14- carbonation based sequence to prepare the starting material, isonicotinic C-14-acid (6). Elaboration of (6) to alpha-bromoacetyl-[C-14] isonipecotic acid (10) via the corresponding diazoketone, followed by intamolecular cyclization, gave the key intermediate 3-quinuclidone-[3-C-14] (3). 3-quinuclidone-[3-C-14] was converted to a mixture of phenethylamine diastereomers. Carrier free crystallization and hydrogenolysis furnished both (R) and (S) 3-aminoquinuclidine-[3-C-14] enantiomers at >99% optical purity.
3-Aminoquinuclidine, an important fragment associated with many 5-HT (serotonin) receptor ligands, has been synthesized using a C-14- carbonation based sequence to prepare the starting material, isonicotinic C-14-acid (6). Elaboration of (6) to alpha-bromoacetyl-[C-14] isonipecotic acid (10) via the corresponding diazoketone, followed by intamolecular cyclization, gave the key intermediate 3-quinuclidone-[3-C-14] (3). 3-quinuclidone-[3-C-14] was converted to a mixture of phenethylamine diastereomers. Carrier free crystallization and hydrogenolysis furnished both (R) and (S) 3-aminoquinuclidine-[3-C-14] enantiomers at >99% optical purity.