INDULINES

indulines, a series of dyestuffs of blue, bluish-red or black shades, formed by the interaction of para-amino azo compounds with primary monamines in the presence of a small quantity of a mineral acid. they were first discovered in 1863 (english patent 3307) by j. dale and h. caro, and since then have been examined by many chemists (see o. n. witt, _ber._, 1884, 17, p. 74; o. fischer and e. hepp, _ann._, 1890, 256, pp. 233 et seq.; f. kehrmann, _ber._, 1891, 24, pp. 584, 2167 et seq.). they are derivatives of the eurhodines (aminophenazines, aminonaphthophenazines), and by means of their diazo derivatives can be de-amidated, yielding in this way azonium salts; consequently they may be considered as amidated azonium salts. the first reaction giving a clue to their constitution was the isolation of the intermediate _azophenin_ by o. witt (_jour. chem. soc._, 1883, 43, p. 115), which was proved by fischer and hepp to be dianilidoquinone dianil, a similar intermediate compound being found shortly afterwards in the naphthalene series. _azophenin_, c30h24n4, is prepared by warming quinone dianil with aniline; by melting together quinone, aniline and aniline hydrochloride; or by the action of aniline on para-nitrosophenol or para-nitrosodiphenylamine. the indulines are prepared as mentioned above from aminoazo compounds: // n------\ nh2·c6h4n2·c6h5 + c5h5nh2 -> hn:c6h3 // \ c6h4, \ n·c6h5 / (aposafranine) or by condensing oxy- and amido-quinones with phenylated ortho-diamines (f. kehrmann, _ber._, 1895, 28, p. 1714): ho\ // o h2n \ \ c6h2 // + \ c6h4 = o// \ oh c6h5nh / o \\ / n·c6h5 \ 2h2o + \\ c6h2 / \ c6h4. ho / \\ n------// the indulines may be subdivided into the following groups:-- (1) benzindulines, derivatives of phenazine; (2) isorosindulines; and (3) rosindulines, both derived from naphthophenazine; and (4) naphthindulines, derived from naphthazine. // n------\ // n------\ nh:c6h3 // \ c6h4 nh:c6h3 // \ c10h6 \ n·c6h5 / \ n·c6h5 / i. benzindulines. ii. isorosindulines. // n------\ // n------\ nh:c10h5 // \ c6h4 nh:c10h5 // \ c10h6 \ n·c6h5 / \ n·c6h5 / iii. rosindulines. iv. naphthindulines. the rosindulines and naphthindulines have a strongly basic character, and their salts possess a marked red colour and fluorescence. _benzinduline_ (aposafranine), c18h13n3, is a strong base, but cannot be diazotized, unless it be dissolved in concentrated mineral acids. when warmed with aniline it yields anilido-aposafranine, which may also be obtained by the direct oxidation of ortho-aminodiphenylamine. _isorosinduline_ is obtained from quinone dichlorimide and phenyl-[beta]-naphthylamine; _rosinduline_ from benzene-azo-[alpha]-naphthylamine and aniline and _naphthinduline_ from benzene-azo-[alpha]-naphthylamine and naphthylamine. indult (lat. _indultum_, from _indulgere_, grant, concede, allow), a, papal licence which authorizes the doing of something not sanctioned by the common law of the church; thus by an indult the pope authorizes a bishop to grant certain relaxations during the lenten fast according to the necessities of the situation, climate, &c., of his diocese.