Patent GB-490372-A (GB)
Title: The manufacture of dyestuffs of the anthraquinone series
IPC: C09B1/40
Filed: 1937-02-12
Abstract: Dyestuffs of the anthraquinone series are manufactured by introducing into the 4-position of a 1-aminoanthraquinone or a substitution product thereof a secondary amino group of the formula <FORM:0490372/IV/1> where X is hydrogen or alkyl, or by introducing an amino group (which may be substituted) into the 1-position of an anthraquinone already containing in the 4-position the secondary amino group specified above.  The introduction of the amino groups is effected by starting from 1-amino-4-halogenanthraquinonesulphonic acids or their derivatives substituted in the 1-amino group, replacing the halogen atom by the above mentioned secondary amino group, and, if desired, splitting off the sulphonic acid group or replacing it by another monovalent substituent, and also, if desired, eliminating the substituent in the 1-amino group; or by starting from anthraquinone derivatives substituted in 1- or 4-position or both by halogen, alkoxy, sulphonic acid or nitro groups, which substituents are replaced by (or reduced to) the said amino group or groups, and, if only one amino group is present in the compound formed, introducing a further amino group in p-position thereto; or by starting from 1 : 4-diaminoleucoanthraquinone and replacing one amino group therein by the above mentioned secondary amino group by heating with 1 : 4-dihydroxyanthraquinone and a suitable alkylamine.  Those of the products which contain water solubilizing groups are acid wool dyestuffs, whilst those free from such groups may be used for dyeing and printing cellulose esters and ethers.  In examples: (1) the sodium salt of 1-amino-4-bromoanthraquinone-2-sulphonic acid is heated in an aqueous medium with isopropylamine, sodium carbonate and cuprous chloride; the product dyes wool blue shades; it may be heated with glucose in an alkali medium to split off the sulphonic acid group, with aqueous potassium cyanide to replace the sulphonic acid group by a cyano group, which is then saponified to a carboxylic amide group, or with ethyl or other alcohol to replace the sulphonic acid radicle by an alkoxy group; the resulting products dye acetate artificial silk bluish violet, greenish blue and reddish violet shades respectively; the starting material may be replaced by its 5-acetylamino derivative; (2) 1-amino-4-bromoanthraquinone-2-sulphonic acid (sodium salt) is reacted as in (1) with sec.-butylamine; the product dyes wool reddish blue shades; by splitting off the sulphonic acid group there is obtained a product which dyes acetate artificial silk reddish blue-violet shades; (3) 1-benzoylamino-4-chloroanthraquinone is heated with aqueous isopropylamine, dioxane and cuprous acetate, and the product is saponified with sulphuric acid; the product dyes acetate artificial silk bluish violet shades; the starting material may contain, in place of the chlorine atom, another replaceable substituent such as a nitro or methoxy group; (4) the potassium salt of anthraquinone-1-sulphonic acid is heated with aqueous isopropylamine, the product is either treated with bromine in glacial acetic acid, then with benzenesulphonamide and saponified, or is nitrated and reduced; in either case there is formed 1-amino-4-isopropylaminoanthraquinone; (5) 1 : 4-diaminoleucoanthraquinone is heated with 1 : 4-dihydroxyanthraquinone, isopropylamine and isobutyl alcohol, and air is then blown in after the addition of cuprous acetate; (6) 1 : 4-diaminoleucoanthraquinone is heated with methylamine (or ethanolamine), isopropylamine, methanol and water, and the product is oxidized as in (5); the products dye acetate artificial silk reddish blue shades.  Specifications 280,637, 322,576, and 323,026, [all in Class 2 (iii)], are referred to.