Comments on a facile conversion of epoxides to halohydrins with elemental halogen using isonicotinic hydrazide (isoniazide) as a new catalyst-a reinvestigation

The reaction of epoxides with bromine or iodine in the presence of isonicotinic hydrazide gives in fact the corresponding 2-halohydrins with reasonable yields, but contrary to the literature statement [H. Sharghi, M.M. Eskandari, R. Ghovami, J. Mol. Catal. A: Chem. 215 (2004) 55-62] the isonicotinic hydrazide is not a catalyst-it is just a stoichiometric reagent which reacts with 2 mol of halogene to give quantitatively the nitrogen, and to generate the hydrogen halogenide, which is a real epoxide ring opening compound.