Patent GB-271906-A (GB)
Title: Manufacture of vat dyestuffs
IPC: C09B7/00
Filed: 1927-05-30
Abstract: 271,906. I. G. Farbenindustrie Akt.- Ges. May 29, 1926, [Convention date]. Thioindigoid dyes.-The following thioglycollic acids are converted into the corresponding oxythionaphthenes and thioindigos :-3 : 5-dimethyl- 4-halogenphenyl-1-thioglycollic acid and 3: 4-dimethyl-5-halogenphenyl-1-thioglycollic acid, or a substitution product of one of these acids having a nitrile group, a CONH2 group or a carboxyl group in the o-position to the thioglycollic acid gxoup, Further, the following oxythionaphthenes or the 2-derivatives of the corresponding 2 : 3-diketodihydrothionaphthenes may be condensed with the usual indigoid dye components :-4 : 6- dimethyl-5-halogen-, and 4 : 5-dimethyl-6-halogen- 3-oxythionaphthenes. The products dye cotton from the vat in red to violet shades fast to light and kier-boiling. According to examples :-(1) 3 : 5-dimethyl-4-chlorphenylthioglycollic acid is treated with chlorsulphonic acid and the resulting oxythionaphthene oxidized with potassium ferricyanide, or air in presence of copper sulphate, to 4 : 6 : 4<1> : 6<1> - tetramethyl - 5 : 5<1>-dichlorthioindigo: (2) 3 :-4-dimethyl-5-chlorphenylthioglycollic-2-carboxylic acid nitrile is converted, by means of sodium sulphide, into the 4 : 5-dimethyl- 6-chlor-3-amino-1-thionaphthene-2-carboxylic acid and the latter heated with dilute hydrochloric acid to obtain the 3-oxy-1-thionaphthene which is then oxidized to the thioindigo : (3) 4-methyl-5: 6-dichlor - 2 : 3 - diketodihydrothionaphthene-2-(p-dimethylamino)-anil is condensed with 4 : 6-dimethyl - 5 - chloro-3-oxythionaphthene ; (4) 4- methyl - 6-chlor-2: 3-diketodihydrothionaphthene- 2-(p-dimethylamino)-anil is condensed with 4 : 5- dimethyl-6-chlor-3-oxythionaphthene. As components for condensing with the oxythionaphthenes are mentioned diketones or their derivatives such as isatins, acenaphthenequinones, and dichlorisatin-chlorides or -anilides. Thioglycollic acids. - 3: 5-Dimethyl-4-chlorphenylthioglycollic acid is obtained by nitrating 1: 3-dimethyl-2-acetylaminobenzene, saponifying the 1 : 3-dimethyl-5-nitro-2-acetylaminobenzene so obtained, substituting chlorine for the amino group, reducing the nitro group and converting the resulting 3: 5-dimethyl-4-chlor-1-aminobenzene into the corresponding 1-thioglycollic acid in the usual way, or by transforming 2: 6-dimethyl-2-aminobenzene into the corresponding thiocyanogen compound, replacing the NH2-group by chlorine, and converting the thiocyanogen group into the thioglycollic acid group. 3 : 4-Dimethyl-5-chlorphenylthioglycollic-2-carboxylic acid nitrile is obtained by converting 1 : 2-dimethyl-3- aminobenzene according to the processes of Specifications 17417/14 and 18292/14 into 2-amino- 3 : 4-dimethyl-5-chlorphenylthioglycollic acid and replacing the NH2-group by CN by way of the diazo compound. Specification 251,996 is referred to. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the conversion of 5-methyl-2 : 4-dihalogenphenyl-, 3-methyl-4-halogenphenyl- and 5-methyl-2-halogenphenyl-1-thioglycollic acids, or the o-derivatives specified above, into the corresponding oxythionaphthenes and thioindigoes and also their condensation with the usual indigoid components; 5-methyl-2:4-dichlorphenyl-, 3-methyl-4-chlorphenyl- and 5- methyl-2-chlorphenyl-1-thioglycollic acids and 3- methyl-4-bromphenyl-1-thioglycollic acid -2-carboxylic acid are used in examples. This subjectmatter does not appear in the Specification as accepted.