Synthesis of 3‑(Hetero)aryl Tetrahydropyrazolo[3,4‑<i>c</i>]pyridines by Suzuki–Miyaura Cross-Coupling Methodology

A new synthetic route to 3-(heteroaryl) tetrahydropyrazolo­[3,4-<i>c</i>]­pyridines has been developed that uses the Suzuki–Miyaura cross-coupling of a triflate <b>6</b> with (hetero)­aryl boronic acids or esters. Using Pd­(OAc)₂ and XPhos or an XPhos precatalyst, a diverse range of substituents at the C3 position of the tetrahydropyrazolo­[3,4-<i>c</i>]­pyridine skeleton were prepared. The use of pivaloyloxymethyl and benzyl protection also offers the potential to differentially functionalize the pyrazole and tetrahydropyridine nitrogens

Optimization of Brain Penetrant 11β-Hydroxysteroid Dehydrogenase Type I Inhibitors and in Vivo Testing in Diet-Induced Obese Mice

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) has been widely considered by the pharmaceutical industry as a target to treat metabolic syndrome in type II diabetics. We hypothesized that central nervous system (CNS) penetration might be required to see efficacy. Starting from a previously reported pyrimidine compound, we removed hydrogen-bond donors to yield <b>3</b>, which had modest CNS penetration. More significant progress was achieved by changing the core to give <b>40</b>, which combines good potency and CNS penetration. Compound <b>40</b> was dosed to diet-induced obese (DIO) mice and gave excellent target engagement in the liver and high free exposures of drug, both peripherally and in the CNS. However, no body weight reduction or effects on glucose or insulin were observed in this model. Similar data were obtained with a structurally diverse thiazole compound <b>51</b>. This work casts doubt on the hypothesis that localized tissue modulation of 11β-HSD1 activity alleviates metabolic syndrome

Design and Optimization of Pyrazinecarboxamide-Based Inhibitors of Diacylglycerol Acyltransferase 1 (DGAT1) Leading to a Clinical Candidate Dimethylpyrazinecarboxamide Phenylcyclohexylacetic Acid (AZD7687)

A new series of pyrazinecarboxamide DGAT1 inhibitors was designed to address the need for a candidate drug with good potency, selectivity, and physical and DMPK properties combined with a low predicted dose in man. Rational design and optimization of this series led to the discovery of compound <b>30</b> (AZD7687), which met the project objectives for potency, selectivity, in particular over ACAT1, solubility, and preclinical PK profiles. This compound showed the anticipated excellent pharmacokinetic properties in human volunteers