Exploring SAR features in diverse library of 4-cyanomethyl-pyrazole-3-carboxamides suitable for further elaborations as CB1 antagonists.

A chemically diverse library of secondary and tertiary 4-cyanomethyl-1,5-diphenyl-1H-pyrazole-3-carboxamides was synthesized to enable mapping of the SAR, in the eastern amide region, with regard to CB1 antagonist activity, This study was initiated as a prelude to the design and synthesis of possible CB1 antagonists that do not readily pass the blood-brain-barrier. In general a range of modifications were found to be tolerated in this part of the molecule, although polar and especially charged groups did to a degree reduce the CB1 antagonistic activity. Several compounds with single-digit or even sub-nanomolar potency, suitable for further elaboration of the nitrile moiety, were identified. Copyright 2009 Elsevier Ltd. All rights reserved.