Patent GB-495375-A (GB)
Title: Manufacture of new vat-dyestuffs of the anthraquinone-acridone series
IPC: C09B5/36
Filed: 1937-05-05
Abstract: Vat dyestuffs of the anthraquinoneacridone series, of the general formula <FORM:0495375/IV/1> where X is hydrogen or a substituent and R is an aromatic radicle containing a trifluoromethyl group, are manufactured by causing a 1 - amino - 4 - halogenanthraquinone - 2-sulphonic acid or a derivative or substitution product thereof to react with an o-amino-carboxylic acid containing a trifluoromethyl group, subjecting the product to ring closure and acylating the resulting 4-aminoanthraquinoneacridone.  In examples: (1) 1-amino-4 - bromanthraquinone - 2 - sulphonic acid is heated with 2-amino-4-trifluoromethylbenzoic acid in the presence of cuprous chloride (or copper powder), potassium acetate and sodium carbonate and the product is heated with sulphuric acid to effect ring closure with simultaneous elimination of the sulphonic acid group; the resulting dyestuff, which dyes cotton from a violet vat greenish blue shades, is heated with benzoyl chloride in nitrobenzene; the product dyes cotton blue shades; (2) the benzoyl chloride in (1) is replaced by o-chlorobenzoyl chloride; the product dyes cotton from a violet vat violet shades; (3) 1-amino-4 - bromo - 5 - acetylaminoanthraquinone-2-sulphonic acid is heated with 2-amino-4-trifluoromethylbenzoic acid in aqueous solution in the presence of potassium acetate and cuprous chloride, and the product is heated with sulphuric acid and then with benzoyl chloride in o-dichlorobenzene in the presence of pyridine; the product dyes cotton in a violet vat blue shades; (4) 1-amino-4-bromo-6 - chloranthraquinone - 2 - sulphonic acid is treated as in (3), the final benzoylation being performed in chlorobenzene; the product dyes cotton and artificial silk blue shades; (5) 1 - amino - 4 - bromanthraquinone - 2-sulphonic acid is reacted with 4-trifluoromethylchloranthranilic acid by the process of (3), and the product is heated with sulphuric acid and then with 3-fluorobenzoyl chloride in o-dichlorobenzene in the presence of pyridine; the product dyes cotton and artificial silk blue shades; the 3-fluorobenzoyl chloride may be replaced by benzoyl or 3-methylbenzoyl chloride; (6) the benzoyl chloride in (1) is replaced by m-toluic acid chloride or m-methoxybenzoyl chloride, or (7) by m-chlorobenzoyl chloride, or (8) by m-fluorobenzoyl chloride; (9) 1 - amino - 4 - bromanthraquinone - 2-sulphonic acid is heated with 2-amino-3-trifluoromethylbenzoic acid in aqueous solution in the presence of potassium acetate and copper powder, and the product is heated with sulphuric acid and benzoylated; the product dyes cotton reddish blue shades; (10) 6 - amino - 3 - trifluoromethylbenzoic acid is employed in the process of (9); (11) 2 - amino - 4 - chloro - 6 - trifluoromethylbenzoic acid is similarly treated; (12) the benzoyl chloride in (1) is replaced by terephthalic, cinnamic, tetrahydrobenzoic, naphthalene-1- or 2-carboxylic or 5 : 6 : 7 : 8-tetrahydronaphthalene-2-carboxylic acid chlorides.  2 - Amino - 4 - trifluoromethylbenzoic acid is obtainable from 2-nitro-4-trifluoromethylaniline by replacing the amino group by cyano, saponifying this and reducing the nitro group.  2- And 6 - amino - 3 - trifluoromethylbenzoic acids are obtainable by nitrating o -trifluoromethylbenzene to form the m-nitro compound, reducing and acetylating, and nitrating the product to yield a mixture of three isomers from which 2- and 6-nitro-3-trifluoromethyl-1-acetylaminobenzene are separated, and are transformed according to the scheme -NHCO CH3 --> -NH2 --> -CN --> -COOH, and finally reduced.  2 - Amino - 4 - chloro - 6 - trifluoromethylbenzoic acid is obtainable by acetylating 6-amino - 3 - chloro - 1 - trifluoromethylbenzene, nitrating, transforming the product according to the scheme -NHCOCH3 --> -NH2 --> -CN --> -COOH, and reducing the nitro group. 4 - Trifluoromethylchloranthranilic acid is obtainable by treating 4-trifluoromethyl-2-acetylaminobenzoic acid with chlorine in the presence of nitrobenzene and iodine and saponifying the product.