Patent GB-675149-A (GB)
Title: Preparation of new vat dyes of the anthraquinone oxazole series
IPC: C09B43/36
Filed: 1950-05-22
Abstract: 4 : 41 - Azobiphenyl - 411 : 4111 - dicarboxylic acid is prepared by reducing 4-(41-nitrophenyl)-benzoic acid with glucose in the presence of sodium hydroxide.ALSO:The invention comprises vat dyes of the general formula <FORM:0675149/IV (c)/1> wherein X represents a hydrogen or halogen atom and R represents a vattable anthraquinone radical, unsubstituted or carrying one or more simple monovalent substituents (e.g. halogen atoms, lower alkyl or alkoxy groups or simple acylamino groups) but not containing halogen in a position ortho to the -CONH-linkage (which is preferably in an a -position); and the manufacture thereof by the following methods: (a) condensing in a non-reactive medium a 4:41-azobiphenyl-411-(1-halogen- or 1 : 3 - dihalogen - 2 - carbonylaminoanthraquinone)-4111-carboxylic acid chloride with an aminoanthraquinone not containing a halogen atom in o-position to the amino group and heating the resulting unsymmetrical amide with an acid binder and a ring-closing catalyst; or (b) condensing a 411-(1 : 2(N)-anthraquinoneoxazolyl) - 4 : 41 - azobiphenyl - 4111 - carboxylic acid chloride (which may contain a halogen atom in the 3-position of the anthraquinone nucleus) with a 1-aminoanthraquinone not containing a halogen atom in the 2-position. In carrying out method (a), 4 : 41-azobiphenyl-411 : 4111-dicarboxylic acid dichloride may be prepared in situ (e.g. by the action of thionyl chloride or phosphorus pentachloride on the free acid or its sodium salt), a 2-amino-1-halogen- or -1 : 3-dihalogen-anthraquinone and the aminoanthraquinone then being added in turn, followed by the catalyst.  Reference is also made to a third process in which a (4 : 41-azobiphenyl - 411 - carbonylamino) - anthraquinone-4111-carboxylic acid chloride not containing a halogen atom in o-position to the azobiphenylcarbonylamino group is condensed with a 2-amino-1-halogen- or -1 : 3-dihalogenanthraquinone and the product is ring-closed to the oxazole as in (a).  Examples describe the use of the following starting materials in method (a): 4 : 41 - azobiphenyl - 411 - (1 - chloro- and 1 : 3 - dibromo - 2 - carbonylaminoanthraquinone)-4111-carboxylic acid chlorides; 1- and 2-aminoanthraquinone and the 4- and 5-benzoylamino, 5 : 8-dibenzoylamino, 6-chloro, 2-methyl and 5-(a -thenoylamino) derivatives of the former.  In a further example, 411-(1 : 2(N)-anthraquinoneoxazolyl) - 4 : 41 - azobiphenyl - 4111-carboxylic acid chloride is heated with 1-aminoanthraquinone in nitrobenzene in the presence of pyridine. Additional starting materials specified are 4 : 41-azobiphenyl-411-(1-bromo-, 1 : 3-dichloro-, 1-bromo-3-chloro- and 1 - chloro - 3 - bromo - 2 - carbonylaminoanthraquinone) - 4111 - carboxylic acid chlorides, and 1 - amino - 4 - methoxyanthraquinone. The products dye cellulose and related fibres from alkaline hydrosulphite vats in yellow tints.  Specifications 487,380 and 508,393 are referred to.  4 : 41 - Azobiphenyl - 411 - (1 - halogen- and 1 : 3 - dihalogen - 2 - carbonylaminoanthraquinone)-4111-carboxylic acid chlorides are obtainable by reacting 4 : 41-azobiphenyl-411 : 4111-dicarboxylic acid dichloride with 1-chloro-, 1-bromo-, 1 : 3-dichloro-, 1 : 3-dibromo-, 1-chloro-3-bromo- or 1-bromo-3-chloro-2-aminoanthraquinone.  411 - (1 : 2(N) - Anthraquinoneoxazolyl) - 4 : 41-azobiphenyl-411-carboxylic acid chloride is prepared by condensing 4 : 41 - azobiphenyl - 411 : 4111-dicarboxylic acid dichloride with 1-chloro-2-aminoanthraquinone, hydrolysing the free -COCl group, closing the oxazole ring by heating with sodium carbonate, potassium acetate, cupric acetate and cuprous chloride, and regenerating the .. COCl group by heating with thionyl chloride in nitrobenzene in the presence of pyridine. Amino-thenoylamino-anthraquinones are obtainable by monothenoylation of diaminoanthraquinones, or by thenoylation of a nitro- or chloro-aminoanthraquinone followed by reduction of the nitro group or replacement of the chlorine by NH2.