Bioisosteric replacement of the hydrazide pharmacophore of the cannabinoid-1 receptor antagonist SR141716A. Part I: potent, orally-active 1,4-disubstituted imidazoles.

A new series of CB(1) receptor antagonists incorporating an imidazole-based isosteric replacement for the hydrazide moiety of rimonabant (SR141716) is disclosed. Members of this imidazole series possess potent/selective binding to the rCB(1) receptor and exhibit potent hCB(1) functional activity. Isopropyl analog 9a demonstrated activity in the tetrad assay and was orally-active in a food intake model.

Discovery of 2-(2-chlorophenyl)-3-(4-chlorophenyl)-7-(2,2-difluoropropyl)-6,7-dihydro-2H-pyrazolo[3,4-f][1,4]oxazepin-8(5H)-one (PF-514273), a novel, bicyclic lactam-based cannabinoid-1 receptor antagonist for the treatment of obesity.

We report the design, synthesis, and structure-activity relationships of novel bicyclic lactam-based cannabinoid type 1 (CB(1)) receptor antagonists. Members of these series are potent, selective antagonists in in vitro/in vivo efficacy models of CB(1) antagonism and exhibit robust oral activity in rodent models of food intake. These efforts led to the identification of 19d, which has been advanced to human clinical trials for weight management.

4-amino-5-aryl-6-arylethynylpyrimidines: structure-activity relationships of non-nucleoside adenosine kinase inhibitors.

A series of non-nucleoside adenosine kinase (AK) inhibitors is reported. These inhibitors originated from the modification of 5-(3-bromophenyl)-7-(6-morpholin-4-ylpyridin-3-yl)pyrido[2,3-d]pyrimidin-4-ylamine (ABT-702). The identification of a linker that would approximate the spatial arrangement found between the pyrimidine ring and the aryl group at C(7) in ABT-702 was a key element in this modification. A search of potential linkers led to the discovery of an acetylene moiety as a suitable scaffold. It was hypothesized that the aryl acetylenes, ABT-702, and adenosine bound to the active site of AK (closed form) in a similar manner with respect to the orientation of the heterocyclic base. Although potent acetylene analogs were discovered based on this assumption, an X-ray crystal structure of 5-(4-dimethylaminophenyl)-6-(6-morpholin-4-ylpyridin-3-ylethynyl)pyrimidin-4-ylamine (16a) revealed a binding orientation contrary to adenosine. In addition, this compound bound tightly to a unique open conformation of AK. The structure-activity relationships and unique ligand orientation and protein conformation are discussed.

Potent and selective, sulfamide-based human beta 3-adrenergic receptor agonists.

A series of sulfamide-based analogs related to L-796568 were prepared and evaluated for their biological activity at the human beta(3)-adrenergic receptor (AR). This modification allows for a significant reduction in molecular weight, while maintaining single-digit nanomolar potencies at the beta(3)-AR and high selectivities versus the beta(2)- or beta(3)-AR.

Discovery of a novel series of 6-azauracil-based thyroid hormone receptor ligands: potent, TR beta subtype-selective thyromimetics.

In this communication, we wish to describe the discovery of a novel series of 6-azauracil-based thyromimetics that possess up to 100-fold selectivities for binding and functional activation of the beta(1)-isoform of the thyroid receptor family. Structure-activity relationship studies on the 3,5- and 3'-positions provided compounds with enhanced TR beta affinity and selectivity. Key binding interactions between the 6-azauracil moiety and the receptor have been determined through of X-ray crystallographic analysis.