88-51-7Relevant articles and documents
ECO-FRIENDLY METHOD FOR PREPARING HIGHLY PURE 2-CHLORO-4-AMINOTOLUENE-5-SULFONIC ACID
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Paragraph 0151-0159, (2017/06/02)
The present invention relates to an eco-friendly method for preparing highly pure 2-chloro-4-aminotoluene-5-sulfonic acid, which includes efficient reaction processes to provide highly pure 2-chloro-4-aminotoluene-5-sulfonic acid without a purification process, and minimizes generation of contaminants by reusing a waste solvent after distillation. The method comprises the steps of: 1) adding 2-chloro-4-aminotoluene, a solvent and sulfuric acid to a reactor; 2) carrying out sulfonation of the reaction materials added to the reactor; 3) filtering and washing the compound produced from the step 2) with a solvent to provide wet cake; 4) vacuum drying the wet cake obtained from the step 3) to provide 2-chloro-4-aminotoluene-5-sulfonic acid; and 5) carrying out distillation of the waste solvent generated from the steps 3) and 4).(AA) Start(BB) End(S10) Add 2-chloro-4-aminotoluene, solvent and sulfuric acid to a reactor(S20) Carry out sulfonation on additive added to the reactor(S30) Filter and wash compound subjected to sulfonation with solvent to obtain wet cake(S40) Vacuum dry wet cake to obtain 2-chloro-4-aminotoluene-5-sulfonic acid(S50) Carry out distillation of waste solvent generated during filtering, washing and vacuum dryingCOPYRIGHT KIPO 2016
The influence of different solvents on 2-ammonio-4-chloro-5- methylbenzenesulfonate, including its De- and resulfonation
Bekoe, Sandor L.,Bats, Jan W.,Alig, Edith,Schmidt, Martin U.
, p. 655 - 663 (2014/01/06)
The title compound (2-ammonio-4-chloro-5-methylbenzenesulfonate), C 7H8ClNO3S, 1, is an intermediate in the synthesis of laked red and yellow azo pigments. Heating 1 in 2-picoline, quinoline and N,N′-dimethylacetamide (DMAc) [or N-methyl-2-pyrrolidone (NMP)] resulted in the formation of three different compounds: a 2-picolinium hydrate (2), a quinolinium quinoline solvate (3), and a sulfate of the desulfonated title compound (4). The three new compounds were structurally characterised using single-crystal diffraction data and chemically using thermal analysis (DTA/TGA), elemental analysis and spectroscopic methods (IR and NMR). By heating 2, 3 and 4 in the solid state, compound 1 is obtained again. In the case of 4, this corresponds to a desulfonation-resulfonation reaction in subsequent steps, which is rarely observed as such. Graphical Abstract: The title compound 2-ammonio-4-chloro-5-methylbenzenesulfonate was heated in 2-picoline, quinoline and N,N′-dimethylacetamide (DMAc) resulting in the formation of three different compounds: a 2-picolinium hydrate (2), a quinolinium quinoline solvate (3), and a sulfate of the desulfonated title compound (4 see Figure). Heating 2, 3 and 4 in the solid state, compound 1 is obtained again. In the case of 4, this corresponds to a desulfonation- resulfonation reaction in subsequent steps, which is rarely observed as such.[Figure not available: see fulltext.]
Mixed coupled azo pigments
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, (2008/06/13)
(1) A mixed coupled azo pigment prepared from: (A) 30% to 70% of two or more diazonium components, at least one derived from a monoaryl amine and (B) an organic coupling component, said pigment containing one or more COOH or SO H groups or esters, amides, alkali metal or alkali earth metal salts thereof or (2) A mixed coupled azo pigment prepared from: (A) 5% to 95% of two or more bis, tris or tetrakis diazonium components, at least one derived from a monoaryl amine and meeting certain specific critria and (B) an organic coupling component, said pigment comprising the same acid or salt groups of pigment (1).
