The structural identification of a methyl analog of methaqualone via 2-dimensional NMR techniques

A submission to the Drug Enforcement Administration North Central Laboratory of a substance believed to be a structural analog of methaqualone hydrochloride precipitated an interest in being able to obtain a rapid and positive identification of such compounds. Both mass spectrometry and proton NMR spectroscopy (1-dimensional) provided evidence to suggest that the structural analog possessed a second methyl group in the molecule, relative to methaqualone, and that the methyl group was attached to the existing methyl-substituted phenyl ring. By application of proton 2-dimensional (2-D) NMR techniques, specifically the homonuclear shift correlation spectroscopy (COSY) and 2-D NOE (NOESY), the precise location of the methyl group in this unknown methaqualone analog was established and shown to have the structure 2.