Synthesis and stereoselective κ-receptor binding of methylated analogues of GR-89.696
作者:Caroline Röhr、Stella Soukara、Bernhard Wünsch
DOI:10.1016/s0223-5234(00)01208-3
日期:2001.2
Stereoselective synthesis of all four stereoisomers of methylated analogues 8 of the kappa -receptor agonist GR-89.696 is presented. Starting with orthogonally protected piperazine derivatives (R,R)-4 and (S,S)-4, the reaction sequence involves oxidation, reductive amination and modification of the piperazine nitrogen protective groups. The configuration of the stereocentre in alpha -position to the pyrrolidine moiety is determined by X-ray structure analysis of (R,S)-8. In receptor-binding studies with the radioligand U-69.593, the stereoisomer with (8)-configuration at both stereogenic centres (S,S)-8 displayed the highest kappa -receptor affinity with a kappa (i)-value of 0.67 nM. (C) 2001 Editions scientifiques et medicales Elsevier SAS.