82-75-7Relevant articles and documents
Preparation method of 1-naphthylamine-5-sulfonic acid
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, (2016/10/17)
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.
Process for the preparation of aminoarylsulphonic acids
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, (2008/06/13)
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.
Fiber-reactive disazo brown dye having vinylsulfone-type reactive group
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, (2008/06/13)
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.
