A. Lifshits, P. N. Ostapchuk, V. K. Brel
Jun 26, 2015
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0
Influential Citations
3
Citations
Journal
Russian Journal of Organic Chemistry
Abstract
Imidazo[1,2-a]pyridine is one of the widely used pharmacophores. Published data contain numerous compounds with imidazo[1,2-а]pyridine fragment possessing different types of bioactivity [1]. The basic and the most investigated method of constructing the bicyclic imidazo[1,2-a]pyridine structure consists in the application of substituted 2-aminopyridines. Various methods of production of one of popular 2aminopyridines, (2-aminopyridin-4-yl)methanol 1, are described in [2–5]. However the basic drawback of the known methods is their multistage character and low efficiency. Unlike the methods applied previously, implying the preliminary acylation of 2-amino-4methylpyridine 2, we developed a method of direct oxidizing the methyl group in compound 1 without preliminary protection of amino group obtaining in one stage 2-aminoisonicotine acid 3, the precursor of alcohol 1. The use of elemental sulfur as an oxidizer [6] made it possible to realize a one-pot synthesis of the methyl ester of 2-aminoisonicotine acid 4, suitable for reduction into the target compound 1 with lithium aluminum hydride (Scheme 1).