“…The position of protonation of 1,1,3,3-tetramethyl-2-nitroguanidine (TMNG) in strong acid has been shown to occur primarily at the dimethylamino site, b. 1 Lockhart,2 however, has presented evidence that proto- nation occurs primarily at the nitrimino site, a, in other methyl nitroguanidines such as l-methyl-2-nitroguanidine (MNG) and l,l-dimethyl-2-nitroguanidine (DM-NG). The evidence presented to support protonation at the amino site for TMNG and at the nitrimino site for MNG and DMNG was based on the proton magnetic resonance spectra of these compounds in concentrated nitric, sulfuric, and hydrochloric acids.…”