Patent GB-291546-A (GB)
Title: Improvements in the manufacture and production of vat dyestuffs
IPC: C09B17/04
Filed: 1927-03-14
Abstract: 291,546. Johnsan, J. Y., (I. G. Farbenindustrie Akt.-Ges.). March 14, 1927. Samples furnished. Dinaphthazine derivatives; azine dyes.-The product obtained by alkaline fusion of 1 : 2 : 1<1> : 2<1>-dinaphthazine-8 : 8<1>-disulphonic acid, which has been found to yield dialkoxydinaphthazines on treatment with alkylating agents and is therefore now regarded as 8 : 8<1>-dioxy-1 : 2 : 1<1> : 2<1>- dinaphthazine, is converted into halogenated products containing more than four halogen atoms in the molecule by vigorous halogenation. The acyl derivatives or the lower halogenated products obtained by the process described in Specification 241,270, may also be used as starting materials. The halogenation may be carried out in a diluent, e.g. acetic anhydride, a halogenated fatty acid, nitrobenzene, a halogenated hydrocarbon, or a mixture of such diluents; halogenation catalysts, e.g. iodine, may also be added. The products are converted into vat dyestuffs with partial removal of the halogen, by treating with agents capable of splitting off hydrogen halide, e.g. concentrated sulphuric acid, inorganic or organic bases, sodium acetate and the like, or by treating with reducing agents, e.g. metals, sulphurous acid and its salts, hydrosulphites, alcohols, phenols, hydrazine and hydroxylamine. The latter operation may in some cases be carried out in two stages, e.g. by treating first with a mild reducing agent, such as sulphurous acid, and then treating the product with an agent serving to split off hydrogen halide, such as boiling aniline. The final products in all cases contain more than four atoms of halogen in the molecule and dye vegetable andanimal fibres from the vat in red shades, with a bluish or yellowish tinge depending on the temperature of the vat. By treatment with concentrated or dilute sulphuric acid, or with organic solvents, the products may, in some cases, be separated into dyestuffs dyeing with a bluish tinge and into those dyeing with a reddish tinge. In examples, (1) 8 : 8<1>-diosy-1: 2 : 1<1> : 2<1> - dinaphtazine is treated with chlorine in boiling acetic anhydride until no more is absorbed; the product, on treatment with alkaline hydrosulphite, passes into solution with the formation of a leuco derivative of a red vat dyestuff, or may be converted into the dyestuff by treatment with sulphuric acid, (2) a similar product is obtained by chlorinating in nitrobenzene; the nitrobenzene solution may be treated with potassium acetate to yield the dyestuff, or the chlorinated derivative may be isolated bv dilution with water and, treated with concentrated sulphuric acid, preferably with the addition of copper powder or stannous chloride, (3) the product obtained in accordance with example 3 of Specification 241,270 is further chlorinated in hot acetic anhydride, and the reaction mixture boiled with glacial acetic acid until more hydrochloric acid is evolved, (4) 8 : 8<1>- dioxy-1 : 2 : 1<1> : 2<1>-dinaphthazine is heated with sulphuryl chloride in nitrobenzene solution with addition of a little iodine, the product is converted into a vat dyestuff by heating with sulphuric acid, or with nitrobenzene and sodium acetate, or by boiling with pyridine, aniline or the like, (5) the acetyl derivative, obtained by boiling the dioxydinaphthazine with nitrobenzene and acetic anhydride is treated with chlorine in nitrobenzene and the reaction mixture is boiled with potassium acetate (6) the benzoyl derivative, obtained by heating with nitrobenzene and benzoyl chloride, is similarly treated, (7) 8: 8<1>-dioxy-1: 2: 1<1>: 2<1>-dinaphthazine is treated with sulphuryl chloride in nitrobenzene and acetic anhydride with addition of iodine, and the reaction mixture is saturated with sulphur dioxide, and finally heated with sodium acetate; trichlorbenzene may be used as diluent instead of a mixture of nitrobenzene and, acetic anhydride, (8) the dioxydinaphthazine is boiled with sulphuryl chloride in the presence of iodine, and the product treated with anhydrous sodium acetate and a mixture of phenol and cresols to yield a dyestuff dyeing cotton in bluish-red shades from the vat, (9) the dioxydinaphthazine is dissolved in dichloracetic acid, treated with chlorine, and the product converted into a vat dyestuff dyeing in yellowishred shades by treating with sulphuric acid and copper powder, or with hydrosulphite and ammonia, or with pyridine and sulphurous acid, (10) the crude dyestuff obtained according to example 7 is treated with concentrated sulphuric acid; the undissolved portion dyes cotton in bluish-red shades, while a dyestuff dyeing in yellowish-red shades can be obtained by diluting the dissolved portion in water.