STUDIES IN INDIGOID DYES. PART V. (METHYL)THIONAPH- THENE-PHENANTHRENE-INDIGOS

Phenanthraquinone and its 2-nitro derivative have been condensed with 4-, 5-, 6-, and 7-methyl­-3-hydroxythionaphthene respectively. The isomeric (methyl)thionaphthene-phenanthrene.-indigos are chocolate and violet dyestuffs, The changes in colour due to the substitution of a methyl group in 4, 5, 6, and 7 positions of the thionaphthene nucleus of some of these dyestuffs were found out by location of their absorption maxima. in the microphotograms. It is revealed that they are of the same order as those of the isomeric indole-(methyl) thionaphthene-indigos, (methyl) thionaphthene­aceanthrylene-indigos, dimethylthioindigos and bis-(methyl)thionaphthene-ethylene-indigospreviously studied by the author