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| | 6-Hydroxynaphthalene-2-sulphonic acid Basic information |
| | 6-Hydroxynaphthalene-2-sulphonic acid Chemical Properties |
| Hazard Codes | Xi | | Risk Statements | 36/37/38 | | Safety Statements | 26-36 | | WGK Germany | 3 |
| | 6-Hydroxynaphthalene-2-sulphonic acid Usage And Synthesis |
| Chemical Properties | 2-Hydroxynaphthalene- 6 -sulfonic acid [93-01-6]. (6-hydroxynaphthalene-2-sulfonic acid), Schaeffer acid, C10H8O4S, Mr 224.23, is readily soluble in water, from which it can be recrystallized as the monohydrate (mp 129℃). The sodium salt is sparingly soluble in cold water (1.7 %) but forms a 30 % solution at 80℃. Coupling with diazo compounds results in substitution in the 1-position as does treatment with bromine, nitrous acid, or oleum. Fusion with potassium hydroxide gives 2,6-dihydroxynaphthalene, amination gives 2- aminonaphthalene-6-sulfonic acid, and sulfonation (20 % oleum, 25℃) results in 2-hydroxynaphthalene-1,6-disulfonic acid. | | Uses | 2-Hydroxynaphthalene-6-sulfonic acid is used as a coupling component for a wide range of azo dyes, e.g., C.I. Acid Orange 12, C.I. Food Yellow 3, and C.I. Food Orange 2. It is also used as an intermediate for more highly substituted dye components and synthetic tanning agents. The 1-nitroso derivative forms an iron complex (C.I. Acid Green 1) which was formerly used as a wool dye. | | Preparation | 2-Naphthol is added to a mixture of sulfuric acid and sodium sulfate, and the reaction is continued at 90 C for 12 h. After pouring the reaction mixture into water, the sodium salt of the product is precipitated by addition of salt and filtered at 60℃ to separate the isomers. |
| | 6-Hydroxynaphthalene-2-sulphonic acid Preparation Products And Raw materials |
| Preparation Products | Sunset Yellow FCF-->Acid Black 26-->7-hydroxynaphthalene-1-sulphonic acid-->Benzoic acid, 2-[(2-hydroxy-6-sulfo-1-naphthalenyl)azo]-, disodium salt-->6-Hydroxy-5-[(2-hydroxy-3,5-dinitrophenyl)azo]-2-naphthalenesulfonic acid sodium salt-->Acid Red 142-->Acid orange 16 (C.I. 16011)-->5-[[4-[(4-Amino-6-sodiosulfo-1-naphthalenyl)azo]-5-methyl-2-methoxyphenyl]azo]-6-hydroxynaphthalene-2-sulfonic acid sodium salt-->4-[(4-Amino-2-chloro-5-methoxyphenyl)azo]-2-ethoxy-2'-hydroxy-[1,1'-azobisnaphthalene]-6,6'-disulfonic acid disodium salt-->SOLVENT VIOLET 2-->2-Naphthalenesulfonic acid, 5,5'-[(2,2'-dimethyl[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[6-hydroxy-, disodium salt-->trisodium 8-[[4-[(4-aminophenyl)azo]-6-sulphonatonaphthyl]azo]-5-[(2-hydroxy-6-sulphonatonaphthyl)azo]naphthalene-2-sulphonate-->Acid alizarin black SN;Mordant black 25-->Acid Blue 26-->Direct black 75 (C.I. 35870)-->2-Naphthalenesulfonic acid, 5-[2-(4-chlorophenyl)diazenyl]-6-hydroxy-, sodium salt (1:1)-->ACID RED 13-->disodium 6-hydroxy-5-[(3-sulphonatophenyl)azo]naphthalene-2-sulphonate-->disodium hydrogen bis[5-[(5-chloro-2-hydroxyphenyl)azo]-6-hydroxynaphthalene-2-sulphonato(3-)]chromate(3-)-->Direct Blue 120:2-->CROCEIN ORANGE G |
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