Efficient Syntheses of Benzothiazepines as Antagonists for the Mitochondrial Sodium−Calcium Exchanger: Potential Therapeutics for Type II Diabetes
摘要:
Type II diabetes mellitus is a chronic metabolic disorder that can lead to serious cardiovascular, renal, neurologic, and retinal complications. While several drugs are currently prescribed to treat type II diabetes, their efficacy is limited by mechanism-related side effects (weight gain, hypoglycemia, gastrointestinal distress), inadequate efficacy for use as monotherapy, and the development of tolerance to the agents. Consequently, combination therapies are frequently employed to effectively regulate blood glucose levels. We have focused on the mitochondrial sodium-calcium exchanger (mNCE) as a novel target for diabetes drug discovery. We have proposed that inhibition of the mNCE can be used to regulate calcium flux across the mitochondrial membrane, thereby enhancing mitochondrial oxidative metabolism, which in turn enhances glucose-stimulated insulin secretion (GSIS) in the pancreatic beta-cell. In this paper, we report the facile synthesis of benzothiazepines and derivatives by S-alkylation using 2-aminobenzhydrols. The syntheses of other bicyclic analogues based on benzothiazepine, benzothiazecine, benzodiazecine, and benzodiazepine templates are also described. These compounds have been evaluated for their inhibition of mNCE activity, and the results from the structure-activity relationship (SAR) studies are discussed.
The Mills reaction and cyclization of readily available 2‐aminobenzyl alcohols and nitrosobenzenes using thionyl bromide provided 2H‐indazoles in up to 88 % yields. In the metal‐free process, acetic acid played a crucial role for the both Mills reaction and cyclization. A brominated 2H‐indazole could also be obtained through the one‐pot sequence.