- Preparation method of 1-naphthylamine-5-sulfonic acid
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The invention discloses a preparation method of 1-naphthylamine-5-sulfonic acid. The preparation method comprises the following steps of step one, sulfonation: refined naphthalene is added after sulfuric acid is added to a sulfonation pot and stirred, steam is turned on for warming, and the reaction is kept for a period of time; then second batch of sulfuric acid is added, and the reaction is kept for a period of time; step two, nitrification: nitric acid is added, the temperature is controlled, and the reaction is kept for a period of time; the acidity is enabled to reach 45%-46%, and the amino value is larger than or equal to 410 g/kg; step three, neutralization: dolomite suspension liquid is added, excess sulfuric acid and hydrogen ions on the sulfonic acid group are neutralized, and the end point is reached if the color of congo red test paper doesn't change into blue; step four, reduction: iron powder is added, the reduction rate is controlled to be above 99%, and the amino value is controlled to be between 90 g/t to 110 g/t; step five, acidification: 1-naphthylamine-8-sulfonic acid is subjected to acidification separation to prepare 1-naphthylamine-5-sulfonic acid mother liquor; step six, the 1-naphthylamine-5-sulfonic acid mother liquor is acidized to further prepare the 1-naphthylamine-5-sulfonic acid.
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- Method for hydrogen catalyzed preparation of 1-naphthylamine-8-sulfonic acid
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The invention discloses a method for hydrogen catalyzed preparation of 1-naphthylamine-8-sulfonic acid. The method includes the reduction steps of: placing a solution containing 1-sulfonyl-8-nitronaphthalene in a reduction pot, adding nickel powder, conducting starting and stirring, enclosing the reduction pot and pumping vacuum, then introducing hydrogen and maintaining the pressure at 1.2-1.3MPa, heating the mixed liquid to a temperature of 100-110DEG C, pumping out the mixed liquid from the bottom continuously and letting it flow into the reduction pot from the top, at the same time pumping out the gas from the top continuously and blowing the gas into the reduction pot from the bottom. The method for hydrogen catalyzed preparation of 1-naphthylamine-8-sulfonic acid provided by the invention can prepare the 1-naphthylamine-8-sulfonic acid product meeting the market requirements, and also can overcome the disadvantages of existing iron powder catalyzed preparation methods.
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- Process for the preparation of aminoarylsulphonic acids
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In the process according to the invention for the preparation of aminoarylsulphonic acids by catalytic hydrogenation of nitroarylsulphonic acids, a substantial increase in the space-time yield in combination with reduced consumption of the catalyst is achieved by dispersing the hydrogen more finely and by limiting according to the invention the concentration of the nitroarylsulphonic acids to be hydrogenated.
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- Solid phase acylation of aminosulfonic acids
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This invention is directed to the acylation of aminosulfonic acids in the solid phase. Two discrete, sequential chemical reactions occur, i.e. (1) the neutralization of the aminosulfonic acid, and (2) the subsequent amine acylation, to produce an improved neutralized acyl-aminosulfonic acid at a reduced cost. Aminosulfonic acids having the general formula HO3 S-A-NH2 are acylated to neutralized acyl-aminosulfonic acids having the general formula RCONH-A-SO3 M, where A is an unsubstituted or substituted aliphatic, aromatic or heteroaromatic group and M is a neutralizing agent moiety. The yield is virtually quantitative.
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- Fiber-reactive disazo brown dye having vinylsulfone-type reactive group
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A compound, or a salt thereof, represented by the following formula, STR1 wherein A is a substituted or unsubstituted phenylene or naphthylene group, B is STR2 in which R3 is a hydrogen atom or a lower alkyl, lower alkoxy, acylamino or ureido group, and R4 is a hydrogen atom or a lower alkyl or lower alkoxy group, R1 and R3 are independently a hydrogen atom or a substituted or unsubstituted lower alkyl group, X is a substituted or unsubstituted amino, lower alkoxy, substituted phenoxy or sulfo group, Y is --SO2 CH=CH2 or --SO2 CH2 CH2 Z, in which Z is a group capable of being split by the action of an alkali, and m is 2 or 3, which is useful for dyeing hydroxyl group- or amide group-containing fiber materials to give dyed products of a brown color having excellent fastness properties with good build-up property.
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- Reactive yellow dye having both monochlorotriazinyl and vinylsulfone type reactive groups
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The compounds represented, in the form of free acid, by the following general formula (I): STR1 (wherein A is STR2 (wherein R3 and R4 are each hydrogen or a methyl, ethyl, methoxy, ethoxy, acetylamino, propionylamino, benzoylamino or ureido group, and R5 and R6 are each hydrogen or a methyl or methoxy group), R1 and R2 are each hydrogen or a methyl, ethyl or sulfomethyl group, X1 and X2 are each hydrogen, chlorine or a methyl, methoxy, carboxyl or sulfonic acid group, m is a number of 0, 1 or 2, and n is a number of 1 or 2, provided that the sum of m and n is 1, 2 or 3). These compounds are capable of dyeing cellulose fibers in yellow with excellent color fastness to hypochlorite, light, perspiration and sunlight and high acid stability.
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