Abstract
By the application of one of α-triphenylguanidine, carbon tetrachloride, or chloroform to lepidine ethiodide in acetic anhydride, in the presence of cadmium carbonate, a dye whose composition and absorption maximum corresponded with 1, 1′, 1″-triethyl-4, 4′-trimethine-10-lepidylquinocyanine diiodide and its intermediate, were obtained. Heating of these two substances with ammoniac water resulted in the transition to a dye whose composition corresponded to 1, 1′, 1″-triethyl-4, 4′-trimethine-10-lepidenylquinolinium iodide. Since the absorption maxima of the two dyes do not differ, the initially obtained dye was assumed to be the so-called Hamer-type neocyanine, or a compound with one mole of hydrogen iodide bonded to the latter dye. Although no final confirmation were obtained, the latter assumption seemed to be the most likely.
