チヤニン色素合成に関する研究 (第19報)

Brooker型色素の合成に関する追補

抄録

Syntheses of the Brooker-type dyes were reported in Part XV and XVI of this series, but some counter-argument has been made against the conclusion of the Brooker-type structure because of the difficulty of the mutual reaction of negative anilino groups and the possibility of another substitution in this synthetic method. The conclusion of the Brooker-type dyes was made from the analytical values and absorption spectra but further proof of the formation of a Brooker-type dye by the substitution of an anilino group in the meso-position was affored by the application of ω-phenylaminovinylbenzothiazolium ethiodide or ω-phenylamino-7-methylbenzothiazolium ethiodide on binuclear trimethinethiocyanine dye possessing inactive methyl in the terminal group and anilino group in the meso-position, to a Brooker-type thiocyanine with a terminal methyl, whose absorption spectrum was similar to or the same as that of binuclear trimethine dyes. It was also experimentally proved that reaction of negative anilino groups does occur by the fact that 1, 1′-diethyl-2, 2′-trimethinethiocyanine iodide was obtained from ω-phenylaminovinyl-benzothiazolium ethiodide and benzothiazole-2-aldehyde p-dimethylaminoanil ethiodide.