A series of novel 4-phenylpiperidinyl and (4-phenylpiperaziny1) alkyl l- phenylcyclopentanecar-boxylates was synthesized and evaluated for affinity at u1 and a2 sites by inhibition of L3H1-(+)-pentazocine (PENT) and PHI-1, 3-di (2-tolyl) guanidine (DTG) binding in guinea pig brain. The phenylpiperidines were more potent u ligands than the corresponding piperazines. Structural modifications varying the optimal spatial distance ...
[Rogers, Gary A.; Parsons, Stanley M.; Anderson, D. C.; Nilsson, Lena M.; Bahr, Ben A.; et al. Journal of Medicinal Chemistry, 1989 , vol. 32, # 6 p. 1217 - 1230]