Solid phase synthesis of 1,5-diarylpyrazole-4-carboxamides: discovery of antagonists of the CB-1 receptor

ACS Comb Sci. 2012 Mar 12;14(3):197-204. doi: 10.1021/co200147y. Epub 2012 Feb 16.

Abstract

We have developed a solid phase synthesis route to 1,5-substituted pyrazole-4-carboxamides with three diversity points aimed at the discovery of new compounds as potential G-Protein coupled receptor (GPCR) ligands. The new chemistry involves acylation of a resin bound secondary amine with a β-ketoester via transamidation, conversion of the resulting β-ketoamide to the corresponding vinylogous amide, pyrazole formation upon reaction with a aryl hydrzine, and cleavage of the product from the resin. Using the reported methodology, we describe the syntheses of multiple arrays of pyrazoles that were used collectively to construct a library of more than 1000 analogues. Several members of this library displayed submicromolar antagonist activities at the cannabinoid subtype 1 (CB-1) receptor.

MeSH terms

  • Amides / chemistry*
  • Amides / pharmacology
  • Drug Discovery*
  • Inhibitory Concentration 50
  • Molecular Structure
  • Protein Binding / drug effects
  • Pyrazoles / chemistry*
  • Pyrazoles / pharmacology
  • Receptor, Cannabinoid, CB1 / antagonists & inhibitors*
  • Receptor, Cannabinoid, CB1 / chemistry
  • Solid-Phase Synthesis Techniques

Substances

  • Amides
  • Pyrazoles
  • Receptor, Cannabinoid, CB1