| Identification | Back Directory | [Name]
7-hydroxynaphthalene-2-sulphonic acid | [CAS]
92-40-0 | [Synonyms]
2-Naphthol-7-sulfonic acid
2-Hydroxynaphthalene-7-sulfonicacid
2-Hydroxynaphthlene-7-sulfonic acid
2-Hydroxy-7-naphthalenesulfonic acid
7-Hydroxynaphthalene-2-sulfonic acid
7-hydroxynaphthalene-2-sulphonic acid
2-Naphthalenesulfonic acid, 7-hydroxy-
(4Z)-4-(phenylmethylene)oxolane-2,3-dione | [EINECS(EC#)]
202-153-0 | [Molecular Formula]
C10H8O4S | [MDL Number]
MFCD16621293 | [MOL File]
92-40-0.mol | [Molecular Weight]
224.23 |
| Hazard Information | Back Directory | [Chemical Properties]
2-Hydroxynaphthalene-7-sulfonic acid [92- 40-0]. (7-hydroxynaphthalene-2-sulfonic acid), F acid, Cassella acid, C10H8O4S, Mr 224.23, is soluble in water, from which it can be recrystallized as the monohydrate (mp 89℃). The sodium and potassium salts are also readily soluble, but the barium salt is sparingly soluble. Iron(III) chloride gives a dark blue color with neutral solutions of 2-Hydroxynaphthalene-7-sulfonic acid. Azo coupling and nitrosation occurs in the 1-position. Sulfonation gives a variety of products depending on the conditions. | [Uses]
2-Hydroxynaphthalene-7-sulfonic acid is used as an intermediate in the production of 2-aminonaphthalene-7-sulfonic acid, 2-hydroxynaphthalene-3,7-disulfonic acid, and 2,7-dihydroxynaphthalene. It has minor uses as an azo coupling component. | [Preparation]
Naphthalene-2,7-disulfonic acid is heated with aqueous sodium hydroxide under pressure at 230℃ for 5 h and then at 260℃ for another 5 h. After neutralizing and screening, the liquor is acidified to precipitate the product, which is isolated after boiling off the sulfur dioxide and cooling to 30℃. |
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