抄録
Coloration of naphthylamines (NA) such as α-naphthylamine (α-NA), β-naphthylamine (β-NA), acetyl-β-naphthylamine, (A-NA) and N-methylene-β-naphthylamine (M-NA) with the Marquis reagent was examined. Among them, β-NA was found to show a specific coloration with the Marquis reagent, and this coloration was useful for the detection of β-NA in a mixture of α-NA and β-NA. By the inspection of ESR spectra of NA, signals at g=2.0020 were observed in all of the colored solution of these NAs with the Marquis reagent, and the coloration of NA with the Marquis reagent was considered to be due to the formation of free radiclas. After decomposition of the colored reaction mixture β-NA with the Marquis reagent, a polymer was obtained, which was insoluble in all organic solvents except DMSO and contained a sulfur atom. The solution of this polymer in sulfuric acid showed an ESR signal at g=2.0020 and the same absorption maximum as the mixture of β-NA and the Marquis reagent. From these results, it was assumed that this coloration is due to the free radical formed from the polymer in surfuric acid.
