New 2,5-dibenzoxazolyl-thiophene derivatives

摘要

The invention comprises compounds of the general formula in which the alkylene groups contain not more than 6 carbon atoms, X stands for a free or neutralized carboxyl group (-COO cation) or a functionally converted carboxyl group, and Z1 and Z2 are identical or different, each representing a hydrogen atom or a methyl group. Specified functionally converted carboxyl groups are carboxylic acid halide groups, carboxylic acid nitrile groups, carboxylic acid ester groups, carbonamide groups and carboxylic acid hydrazide groups. The compounds are prepared by reacting an ortho-hydroxy-aminobenzene of the formula with a dicarboxylic acid of the formula or a functional derivative thereof in a molar ratio of 2:1 at an elevated temperature and preferably in the presence of a catalyst, with or without isolation of the intermediate acylamino compound of the formula and, if desired, converting in the resultant product a free carboxyl group into a functionally converted carboxyl group or hydrolyzing a functionally converted carboxyl group or converting it into another functionally converted carboxyl group, X, Z1, Z2 and the alkylene groups being as defined above. Preferred orthohydroxy-aminobenzenes are those of the general formula in which the alkylene group contains 1-6, preferably 2, carbon atoms and X1 preferably represents a carboxylic acid nitrile, carbonamide or carboxylic acid ester group, these compounds being obtainable by coupling a diazonium salt such as diazotized aniline with a hydroxy compound of the formula and splitting the resulting azo compound by reduction with, for example, sodium hydrosulphite, to the corresponding amine. Examples are given. The compounds of the invention are used as optical brightening agents (see Divisions B5, C3, C4, C5 and D1).ALSO:Compounds of the general formula in which the alkylene groups contain not more than 6 carbon atoms, X stands for a free or neutralized carboxyl group (-COO cation) or a functionally converted carbonyl group, and Z1 and Z2 are identical or different, each representing a hydrogen atom or a methyl group, are used for optically brightening alkyd resin lacquers or synthetic fibres such as polyamides and polyesters. The brightening agents may be incorporated in the reaction batch before the condensation to form the polymer is performed. Example (6) describes the preparation of a brightened fibre from a polyamide, titanium dioxide and a brightening agent.ALSO:Compounds of the general formula in which the alkylene groups contain not more than 6 carbon atoms, X stands for a free or neutralized carboxyl group (-COO cation) or a functionally converted carboxyl group, and Z1 and Z2 are identical or different, each representing a hydrogen atom or a methyl group, are used as optical brightening agents in admixture with dyestuffs or pigments, as additives to dye-baths, printing, discharge or resist pastes, or in combination with detergents such as soaps, salts of sulphonate detergents such as sulphonated 2-(higher alkyl)-benzimidazoles and salts of mono-carboxylic acid esters of 4-sulphophthalic acid with higher fatty alcohols, salts of fatty alcohol sulphates, alkylarylsulphonic acids, condensation products of higher fatty acids with aliphatic hydroxysulphonic or aminosulphonic acids, and non-ionic detergents such as polyglycol ethers derived from ethylene oxide and higher fatty alcohols, alkylphenols or fatty amines. Example (9) describes a soap containing a brightening agent.ALSO:Compounds of the general formula in which the alkylene groups contain not more than 6 carbon atoms, X stands for a free or neutralised carbonyl group (-COO cation) or a functionally converted carbonyl group, and Z1 and Z2 are identical or different, each representing a hydrogen atom or a methyl group, are used in admixture with chemical bleaches, as additives to bleaching baths, or for optically brightening synthetic fibres such as cellulose propionate, acetyl-cellulose, polyamides, polyesters, polyolefines, polyvinyl chloride and polyvinylidene chloride. The brightening agent is preferably suspended in an aqueous medium which may also contain dispersing agents, the fibre being present as style fibres, continuous filaments, in the raw state, or in the form of hanks or fabrics. In examples describe (7) the treatment of a woven fabric of polyamide style fibre yarn in a bath containing brightening agent and acetic acid; (8) the washing of acetate rayon or cotton with a soap containing a brightening agent.