An improved synthesis of m-hydroxymexiletine, a potent mexiletine metabolite.

m-Hydroxymexiletine (MHM), a minor metabolite of the class IB anti-arrhythmic drug mexiletine, is about two fold more potent than the parent compound on human cardiac voltage-gated sodium channels (hNav1.5), and equipotent to mexiletine on human skeletal-muscle voltage-gated sodium channels (hNav1.4). Herein, an alternative and simplified synthesis of this promising compound has been accomplished. This route, as well as being more efficient, has the advantage, over the first, to avoid the use of oxidizing agents, such as the meta-chloroperoxybenzoic acid.