Patent GB-412920-A (GB)
Title: New anthraquinone dyes
IPC: C09B1/58
Filed: 1932-12-30
Abstract: Anthraquinone dyes of formula <FORM:0412920/IV/1> wherein AQ stands for anthraquinonyl or substituted anthraquinonyl residue and R and R<1> are hydrogen or alkyl, are prepared by condensing (a) a halogenanthraquinone with a compound of the formula <FORM:0412920/IV/2> and hydrolysing the product, (b) a halogen anthraquinone with a compound of the formula <FORM:0412920/IV/3> wherein X is an amino group or a nitro group which is subsequently reduced, or (c) a mercaptoanthraquinone with a compound of the formula <FORM:0412920/IV/4> the nitro group being subsequently reduced.  The mercaptoketodihydrobenzthiazines used as starting materials are prepared by converting the corresponding amino compounds to mercapto derivatives by diazotization and treatment with xanthates followed by hydrolysis (if desired, the products being further oxidized, reduced with alkali sulphides, and then condensed with a monohalogenoacetic acid or alkyl derivative thereof), while the nitromercaptoarylthioglycollic acids are prepared from the corresponding nitroaminoarylthioglycollic acids (cf. Specification 406,281); by reduction the corresponding aminomercaptoarylthioglycollic acids are obtained, these being also derived by hydrolysis of the foregoing mercaptothiazine derivatives. In examples: (1) bis-(3-keto-2.3-dihydrobenz - 1 . 4 - thiazine) - 7 . 7<1> - disulphide is condensed with 1-bromo-4-methylaminoanthraquinone and 1 . 5-dibromo-4 . 8-dimethyldiaminoanthraquinone and the respective products saponified by caustic soda; (2) 6 - mercapto - 3 - keto - 2 - ethyl - 2 . 3 - dihydrobenz - 1 . 4 - thiazine (prepared by condensing 2 . 4 - dinitrophenylmercaptan with a -bromobutyric acid followed by reduction with iron and hydrochloric acid to give 6-amino-3-keto-2-ethyl-2 . 3 -dihydrobenz - 1 . 4 - thiazine which is converted to the 6-mercapto body by diazotisation and reaction with a xanthate) is condensed with 2-chloroquinizarin, 2 - 3 - dichloro - 1 . 4 - diaminoanthraquinone, a -chloranthraquinone, and the respective products saponified by caustic soda; (3) 7 - mercapto - 3 - keto - 2 - ethyl - 2 . 3 - dihydrobenz - 1 . 4 - thiazine (prepared by condensing 2 . 5 - diaminophenylmercaptan (Specification 394,312) with a -bromobutyric acid, ring-closing by hot dilute mineral acid and converting the 7-amino body to the 7-mercapto compound) is condensed with 2-chlorquinizarin and a -chloranthraquinone, and the respective products saponified with caustic soda: (4) 6 - mercapto - 3 - keto - 2 . 3 - dihydrobenz - 1 . 4 - thiazine is condensed with 2-chlorquinizarin and 2 . 3 - dichloro - 1 . 4 - diaminoanthraquinone and the products saponified with caustic soda; (5) 1-amino-5-mercaptoanthraquinone is condensed with 5-chloro-2-nitrophenylthioglycollic acid (prepared by condensing 4-nitro-3-chloraniline with thioglycollic acid, diazotising and treating the diazo body with cuprous chloride) and the product reduced with sodium sulphide; (6) 1-bromo-methylaminoanthraquinone is condensed with 2-nitro-4-mercaptophenylthioglycollic acid and the product reduced with sodium sulphide.  The dyes are applied to the fibre from an acid bath and subsequently fixed by after treatment with dilute mineral acids.  The Provisional Specification includes also the manufacture of dyes of the first general formula wherein R and R<1> stand for aryl or aralkyl.  Specifications 377,740 and 406,689 also are referred to.