cas 88-53-9, 2-Amino-5-chloro-4-methylbenzenesulfonic acid

Articles about 88-53-9Total 5 be found

Method for preparing CLT acid by taking m-toluidine as raw material
The invention discloses a method for preparing CLT acid by taking m-toluidine as a raw material, and belongs to the field of chemical synthesis. The method solves the problems that existing CLT acid production is low in yield, not environmentally friendly and the like. The method comprises: S01) an acylation step, namely a step of reacting m-toluidine and acetic anhydride to obtain acylation reaction solution; S02) a chlorination step, namely a step of adding acetic acid and concentrated hydrochloric acid into the acylation reaction solution, then adding hydrogen peroxide, and finally adding an aqueous solution containing sodium sulfite to obtain a chlorination reaction solution; S03) a hydrolyzing step to form salt, namely a step of adding concentrated sulfuric acid into the chlorinationreaction solution, and removing the solvent after reaction; S04) a transposition sulfonation step, namely a step of adding chlorobenzene into the solvent-removed reaction solution obtained in the stepS03, heating the mixture, adding dichlorobenzene, heating the mixture again, reacting the mixture for 7-10 hours with the temperature of the system being maintained at a temperature higher than 170 DEG C, and stopping heating; and S05) a step of post-treatment to obtain a finished product that is the CLT acid. The method has the advantages of environmental protection and the like.
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Paragraph 0053; 0059-0060

(2019/12/02)

A continuous catalytic hydrogenation reduction for preparing CLT acid
The invention discloses a method for preparing CLT acid through continuous catalytic hydrogenation reduction. The method is performed in a set of ejecting circuit continuous reactor, adopts the ejecting circuit continuous reactor to simplify the catalytic hydrogenation reduction process flow and improve the hydrogenation reduction efficiency. Meanwhile, the method can effectively reduce spillage and loss of a catalyst, caused by frequent filtering during intermittent catalytic hydrogenation reduction to realize internal recycling of the catalyst so as to prolong the service life of the catalyst. In addition, when the method is used for preparing CLT acid through continuous catalytic hydrogenation reduction, a reaction kettle is relatively small in size, good in reaction stability, relatively low in dechlorination products in a reaction product, high in selectivity, less in by-products and relatively low in content of residual main nitro compounds, and the nitro conversion rate can be higher than 99.80%.
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Paragraph 0034; 0035; 0036; 0037; 0038; 0039-0046

(2017/08/25)

Method for achieving pipe-type continuous production of CLT acid nitride
The invention discloses a method for achieving pipe-type continuous production of CLT acid nitride. The method comprises the steps that 1, methylbenzene and sulfuric acid conduct a sulfonation reaction in a sulfonation pipe reactor; 2, thth sulfonation reaction solution obtained in the first step and chlorine are continuously fed into a chlorination pipe reactor for a chlorination reaction; 3, the chlorination reaction solution obtained in the second step and nitric acid are continuously fed into a nitrification pipe reactor for a nitrification reaction, and then the CLT acid nitride is prepared. According to the method for achieving pipe-type continuous production of the CLT acid nitride, purification treatment does not need to be conducted on an intermediate in the reaction process, operation is easy, the reaction efficiency is high, and the objective product selectivity is high.
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Paragraph 0079

(2016/11/17)

Azo pigment compositions and process for their preparation
This invention is that of an azo pigment composition containing about 1 to 10 percent by weight of a nonionic alkyl polyglycoside dispersing agent. The polyglycosides useful in the invention have the general formulae: wherein: M is an oxygen, sulfur, nitrogen phosphorous or silicon atom; n is an integer from 8 to 18, preferably 8 to 11 and X represents the number average degree of polymerization having a numerical value from about 1 to about 2. These azo pigment compositions are prepared by conducting the azo pigment coupling reaction in the presence of said alkyl polyglycoside. The resulting pigment exhibit superior application properties in water based ink systems.
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(2008/06/13)

Process for the preparation of aminoarylsulphonic acids in sulfolene solvent
Aromatic aminosulphonic acids which have a reduced content of discoloring by-products are obtained when aromatic amines are reacted with a sulphonating agent in a reaction medium at least some of which consists of tetramethylene sulphone.
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(2008/06/13)