Novel potent antagonists of human neuropeptide YY5 receptors. Part 3: 7-methoxy-1-hydroxy-1-substituted tetraline derivative

As a part of our continuing research on NPY-Y5 receptor antagonists in the series of novel 6-methoxybenzo[a]cycloheptene derivatives, we discovered a novel skeleton, 7-methoxy-1-hydroxytetraline 7 which had been used as an intermediate, to be more suitable for increasing potencies leading to compound 3 (FR230481). Additionally. we discovered that the naphthalenesulfonamide moiety which was thought to be an essential pharmacophore could be replaced by the 5-chlorobenzothiazolin-3-acetic acid moiety to lead to potent compound 4 (FR233118). The structure-activity relationships on compounds 3, 4 and their related derivatives are described. Unfortunately. although compounds 3 and 4 had very high affinities for Y5 receptors, their poor permeabilities to brain were shown by exo-vivo binding assays when orally administered. (C) 2002 Elsevier Science Ltd. All rights reserved.