Patent GB-305498-A (GB)
Abstract: 305,498. Imray, O. Y., (I. G. Farbenindustric Akt.-Ges.). Oct. 28, 1927. Diazo compounds; azo dyes. - Stable diazo compounds derived from p-amino-azo bodies containing no sulphonic or carboxylic groups but containing an alkoxy, aralkoxy, or aryloxy group in o-position to the amino group are obtained in solid form by adding an alkali halide, sulphuric acid and/or a sulphate, a heavy metal salt, or an arylsulphonate to the diazo solution. They may he mixed with partly or totally anhydrous salts and are used for producing azo dyestuffs on the fibre. In examples, (1) the diazonium chloride of 4-nitrobenzene-azo-4<1>-amino-3<1>- methoxy-6<1>-methylbenzene is isolated by adding common salt to its solution; (2) a diazonium bromide solution of 2-chlorbenzene-azo-4<1>- amine-31 : 6<1>-dimethoxybenzene is salted out with potassium bromide ; (3) the diazonium chloride or fluoride of 4-nitro-2-methylbenzeneazo-4<1>-amino-3<1>-methoxy-6<1>-methylbenzene is obtained as in example 1; (4) the diazonium chlorides of 2-chlorobenzene-azo-4<1>-amino-3<1>- ethoxynaphthalene and 3-nitrobenzene-azo-4<1>- amino-3<1>-methoxybenzene are obtained as in example 1; (5) the diazonium sulphate of 2- nitrobenzene - azo - 4<1> - amino - 3<1 >- methoxy-6<1>- methylbenzene, obtained from the diazonium chloride solution and sulphuric acid, is mixed with partly dehydrated aluminium sulphate: (6) the diazonium sulphate of 4-nitrobenzene-azo-4<1>- amino-3<1> : 6<1>-dimethoxybenzene is obtained from the diazonium chloride solution and sulphuric acid and/or sodium sulphate: (7) the diazonium sulphate of 2-methoxybenzene-azo-4<1>-amino-3<1>- methoxvbenzene is salted out with sodium sulphate : (8) the diazonium sulphates of 4-nitrobenzene - azo - 4<1> - amino - 3<1> - ethoxy-6<1>-methylbenzene and 2-chlorobenzene-azo-4<1>-amino-3<1>- ethoxynaphthalene. prepared by adding the diazo solutions to ice water, are mixed with partly dehydrated aluminium sulphate : (9)-(11) the zinc chloride double salts of the diazonium chlorides of 3-nitrobenzene-azo-4<1>-amino-3<1>-methoxyben - zene, 4-nitrobenzene-azo-4<1>-amino-3<1> : 6<1>-dimethoxybenzene, 2-methoxy-4- (or 5-) nitrobenzeneazo-4<1>-amino-3<1> : 6<1>-dimethoxybenzene, 2- (or 4-) nitrobenzene-azo - 4<1> - amino - 3<1> : 6<1> - diethoxybenzene. 2-chlorbenzene-azo-4<1>-amino-3<1>-ethoxynaphthalene and 1- (or 2-) naphthalene- or 4- nitro - 1 - naphthalene - azo - 41 - amino-31 : 61- dimethoxybenzene are prepared from the respective diazonium chloride solutions, zinc chloride, and common salt: (12), (13) the stannic chloride double salts of the diazonium chlorides of 2- chlorobenzene - azo - 4<1> . amino - 3<1> - methoxy - 6<1>-methylbenzene and 2-methoxybenzene-azo-4<1>- amino-3' : 6<1>-dimethoxybenzene are prepared from the respective diazonium chloride solutions and stannic chloride; (14) the zinc chloride double salts of the diazonium chlorides of 4- nitrobenzene - azo - 4' - amino - 3<1> - methoxy-61- methylbenzene and of the p-aminoazo compounds obtained by coupling diazotized 4. (or 5-) nitro- 2 - aminoanisole, 1- or 2-naphthylamine, or 4-nitro-1-naphthylamine with p-cresidine are prepared as in example 10; (15) the solution of the diazonium chloride of 4-nitrobenzene-azo-4<1>. amino-3<1>-methoxy-6<1>-methylbenzene is treated with a concentrated solution of sodium benzene sulphonate; (16) the diazonium chloride of 5- chloro - 2-methoxybenzene - azo - 4<1> - amino- 31: 6'-dimethoxybenzene is separated by means of sodium-p-chlorobenzenesulphonate ; (17) the diazonium chloride of 2-nitrobenzene-azo-4<1>-amino 3<1>-ethoxy-6<1>-methylbenzene is separated by means of sodium 2: 7-naphthalene-disulphonate; (18) the diazonium chloride of 2-chlorobenzeneazo-4<1>-smino-3<1>-methoxybenzene is isolated by means of sodium 1: 5-naphthalenedisulphonate; (19) the zinc chloride double salt of the diazonium chloride of 2-phenoxybenzene-azo-4<1>-amino-3<1>- phenoxybenzene is prepared as in example 10; (20) the diazonium chloride of 4-nitrobenzeneazo - 4<1>-amino-3<1>-benzyloxy-6<1>-methylbenzene is salted out with sodium chloride. Specifications 1645/96 and 214,516 are referred to. 2-Methoxybenzeneazo - 4<1> - amino-3<1>-methoxybenzene is prepared from o-anisidine in a manner analogous to that by which aminoazobenzene is made. 4-Methyl-2-amino-1-benzyloxybenzene, required for manufacture of the parent material in example 20, is obtained by reducing the nitro group of the product of condensation of the potassium salt of 3-nitro-4-cresol with benzyl chloride.