Synthesis and anxiolytic activity of N-substituted cyclic imides (1R*,2S*,3R*,4S*)-N-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-2,3- bicyclo[2.2.1]heptanedicarboximide (tandospirone) and related compounds.

A series of cyclic imides bearing a omega-(4-aryl and 4-heteroaryl-1-piperazinyl)alkyl moieties was synthesized and tested in vivo for anxiolytic activity. The in vitro binding affinities of these compounds were also examined for 5-HT1A receptor sites. Structure-activity relationships within these series are discussed. One of these compounds, (1R*,2S*,-3R*,4S*)-N-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-2,3- bicyclo[2.2.1]heptanedicarboximide (1: tandospirone), was found to be equipotent with buspirone in its anxiolytic activity and more anxio-selective than buspirone and diazepam. Tandospirone (1) is currently undergoing clinical evaluation as a selective anxiolytic agent.     

Diastereoselective synthesis of (R*,R*)-ethyl 2-[1H-indol-3-yl(phenyl)methyl]-3-oxobutanoate

Russian Chemical Bulletin -     

Combinatorial solution-phase synthesis of alkyl (1S*,2S*,3R*,5R*,6R*)-1-alkyl-3-aryl-6-benzoylamino-1-hydroxy-7- oxo-5-phenylhexahydropyrazolo[1,2-a]pyrazole-2-carboxylates

Combinatorial solution-phase cycloadditions of (1Z,4R*,5R*)-4-benzoylamino-5-phenylpyrazolidin-3-on-1-azomethine imines 3 to beta-keto esters 4 afforded a library of 26 bicyclic pyrazolidinones 5 in 6-89% yields and in 14-100% de. All products were isolated in >90% purity according to 1H NMR, and 25 of them were analytically pure. The structures of cycloadducts were confirmed by NMR and X-ray diffraction. Most of the products were isolated as mixtures of the major (1S*,2S*,3R*,5R*,6R*)-epimers 5 and the minor (1R*,2S*,3R*,5R*,6R*)-epimers 6. Epimerization of cycloadducts 5/6 at the anomeric position 1 in solution was confirmed by 1H NMR.