Mauvaniline,(see Rosaniline residues).—The precipitates contaiaing rosaniline and mauvaniline are submitted to the action of hydrochloric acid, salt, 81c., so as to separate them as completely as possible ; the mauvaniline is washed with benzol, and digested in a cohobator with alcoholic potash, by which the free base is obtained. It is washed with water, and when dissolved in acid, dyes magni ficent mauve shades. Accordiog to Girard aad De Laire, 12 per cent. of this is obtained from rosaniline refuse.
Triphenyl-mauvaniline yields salts soluble in alcohol ; they have a beautiful hlue colour.
Ethyl-mauvaniline.—By treating mauvaniline with iodide of ethyl, Girard and De Laire obtain a violet colour, which is bluer according as the iodide is iu greater proportion to the mauvaniline salt. It may be made in the same way as Hofmann's violet (q. v.), with 1 kilo. mauvaniline, 10 lit. wood-spirit, 3 kilo. iodide ethyl (or methyl), and 1 kilo. potash or soda.
Violet cle Paris.—Poirrier and Chappat's violets are obtained from methy.l-anilines ; according to the predominance of blue or violet tints, reddish blues, blues, and pure violets are produced. It is highly probable that for blues aad violets, this is destined to become a very important source. To obtain violet, violet-red, and violet-blue, from methylia, methyl-ethylic, and methyl-amylic anilines, 1 part methyl or dimethyl-aniline, and 5-6 parts anhydrous bichloride tin are mixed in a still, heated up to 100° (212° F.) for sorne hours, and well stirred until hard ; the mass is treated with caustic alkali, washed and filtered ; the precipitate is boiled in water, and neutralized ; from this solution, filtered when cool, common salt throws down a green precipitate, which is collected on a filter, and may be further purified by crystallizing from solution in alcohol; its solution in boiling. water dyes a magnificent violet.
If the heating has been sufficient, the mixture is found as a black tarry mass. Instead of bichloride tin and bichloride mercury, arsenic, acid may be used ; or if 100-150 parts chlorate potash, 100 parts methyl-aniline, and 100 parts water are used, the reaction which follows from the splitting up of the liberated chloric acid yields the colour. Chloride iodine diffused in 5-10 parts of water may also be used ; or a mixture of 80 parts chlorate potash, 20 parts iodine, and 100 parts methyl-aniline. Iodates, bromates, and iodic and bromic acids react on methyl-aniline salts with the same development of colouring matter. Bichloride of mercury alone develops very little colour ;
terchloride benzol and terchlorophenic acid develop a violet, at 150° (302° F.). Red violets are obtained by employing methyl-aniline and bluer violets, when dimethyl-aniline, or higher methylic homologues, are used. After purification, these violets are all soluble in water, alcohol, and acetic acid, and are used for dyeing and printing as other aniline dyes. Brooman's improvements (1866, No. 3195) consist in treating chlorides of methyl-anilines with nitrate or chloride of copper for violets, which yield bluer shades according as the heating is prolonged. The oxidation products from these violets give, with chloride-benzyl, still bluer shades of violet. The methyl and ethyl violets met with in commerce are R. B. BB., to 6B. Bardy obtains violets from methyl-diphenyl amine (q. v.), which are also capable of yielding mixtures of blue and violet.
Girard and De Laire's violet from methyl-benzyl-phenyl-amine may be thus produced :— Methyl-benzyl-diphenyl-amine, 15 lb. ; chlorate potash, 2i lb.; water, 40 lb. ; and non-calcareous sand, 100 lb., are well mixed, placed in a cohobating apparatus, and heated ; a solution of sulphate of copper (5 lb. to 15 lb. water) is added during the heating, ia small portions at a time. Tbe temperature is kept for twenty-four to thirty hours at 50°-80° (122°476° F.); when the reaction is complete, the mixture is carefully neutralized with caustic soda or pOtash, Or lime water, and the unaltered portions of the bases are removed by distilling with a jet of steam. The mass is then treated with hydrochloric acid in slight excess, and the colouring matter is removed by hot water, and thrown down with common salt ; it is then converted into a base by soda or potash ; this is well washed, and again converted into hydrochlorate or acetate. These salts are soluble in water, and dye blue-violet. The colours obtained from the corresponding compounds may be produced in the same way by substituting the alkaloid or its salt ; benzyl-diphenyl-amine gives a bluish green or greenish blue ; benzyl-phenyl-toluyl-amine, orange; benzyl-ditoluyl-amiac, brown or chestnut ; methyl-diphenyl-amine, blue. This same process is, according to Bolley and Kopp, employed by Poirrier for the manufacture of violets from methyl and di-methyl-anilines (q. v.; also violet de Paris).