Remarkably fast and selective aromatization of Hantzsch esters with MoOCl4 and MoCl5: A chemical model for possible biologically relevant properties of molybdenum-containing enzymes

Mo(VI) and Mo(V) salts both react selectively with Hantzsch esters to produce substitute pyridines in good-to-excellent yield (75–99%). The remarkable reactivity and selectivity of MoOCl4 under reflux of acetonitrile and MoCl5 in dichloromethane at room temperature encouraged us to propose that molybdenum-containing enzymes (such as xanthine or aldehyde oxidase) also participate to some degree in the metabolism of 1,4-dihydropyridine drugs in the liver analogous to NADH in the respiratory chain.

Selective aromatization of Hantzsch esters with MoOCl4 or MoCl5 is described. The reaction employing MoOCl4 proceeds smoothly under reflux of acetonitrile within 1–20 min and the products of high purity were isolated in good-to-excellent yields (70–99%). From the obtained results it is proposed that molybdenum-containing enzymes also participate in the metabolism of 1,4-dihydropyridine drugs.Figure optionsDownload as PowerPoint slide