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| | 1,8-Dihydroxynaphthylene-3,6-disulfonic acid Basic information |
| Product Name: | 1,8-Dihydroxynaphthylene-3,6-disulfonic acid | | Synonyms: | 4,5-dihydroxy-7-naphthalenedisulfonicacid;7-Naphthalenedisulfonicacid,4,5-dihydroxy-2;Chrmotropicacid;4,5-Dihydroxy-2,7-naphthalene disulfonic acid
1,8-Dihydroxynaph-thalene-3,6-disulfonic acid;4,5-DIHYDROXY-2,7-NAPHTHALENEDISULFONIC ACID;4,5-dihydroxynaphthalene-2,7-disulphonic acid;1,8-DIHYDROXYNAPHTHALENE-3,6-DISULFONIC ACID;1,8-DIHYDROXYNAPHTHYLENE-3,6-DISULFONIC ACID | | CAS: | 148-25-4 | | MF: | C10H8O8S2 | | MW: | 320.3 | | EINECS: | 205-712-7 | | Product Categories: | Intermediates of Dyes and Pigments | | Mol File: | 148-25-4.mol |  |
| | 1,8-Dihydroxynaphthylene-3,6-disulfonic acid Chemical Properties |
| | 1,8-Dihydroxynaphthylene-3,6-disulfonic acid Usage And Synthesis |
| Chemical Properties | 4,5-Dihydroxynaphthalene-2,7-disulfonic acid [148-25-4]. (1,8-dihydroxynaphthalene-3,6-disulfonic acid), chromotropic acid, C10H8O8S2, Mr 320.3: the disodium salt is readily soluble in water. Alkali fusion yields 1,3,8-trihydroxynaphthalene-6-sulfonic acid. Diazo coupling occurs in the 3- and 6-positions. | | Uses | Chromotropic acid is used as an analytical reagent and as a coupling component for a wide range of azo dyes, e.g., C.I. Acid Violet 6, C. I. Mordant Blue 13, and C.I. Direct Blue 84. | | Definition | ChEBI: A naphthalenesulfonic acid that is naphthalene-2,7-disulfonic acid substituted by hydroxy groups at positions 4 and 5. | | Production Methods | 2-Hydroxynaphthalene-3,6,8- trisulfonic acid total liquor is concentrated and heated with caustic soda liquor to 158℃ for 20 – 30 h . The melt is diluted with water and poured into excess hydrochloric acid. Salt is added, sulfur dioxide expelled, and the mixture cooled to precipitate the product as the disodium salt in 88 % yield.
An alternative process is based on direct fusion (caustic liquor at 228℃ under pressure) of 1-aminonaphthalene-3,6,8-trisulfonic acid to chromotropic acid without isolating the intermediate oxy Koch acid. |
| | 1,8-Dihydroxynaphthylene-3,6-disulfonic acid Preparation Products And Raw materials |
| Raw materials | Naphthalene-2,7-disulfonic acid-->Koch acid-->1-Amino-8-hydroxynaphthalene-3,6-disulphonic acid-->3,5-Dibromotoluene-->Benzenesulfonic acid | | Preparation Products | Mordant Blue 13-->ARSENAZO III-->CHROMOTROPE 2R-->ACID VIOLET 7-->tetrasodium [mu-[[3,3'-[(3,3'-dihydroxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[4,5-dihydroxynaphthalene-2,7-disulphonato]](8-)]]dicuprate(4-)-->Mordant Blue 13-->3-[(4-Formylphenyl)azo]-4,5-dihydroxy-2,7-naphthalenedisulfonic acid disodium salt-->DIRECT BLUE 25-->ACID RED 60-->Direct Black 27-->Acid chrome blue K-->Portofino Blue ES-->Mordant Blue 6-->4,5-Dihydroxy-3-[[4'-[(2-hydroxy-6-sodiosulfo-1-naphthalenyl)azo]-1,1'-biphenyl-4-yl]azo]naphthalene-2,7-disulfonic acid disodium salt-->C.I. Direct blue 49-->Acid Violet 20-->CHROMOTROPE 2R |
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