| Identification | Back Directory | [Name]
1-Hydroxynaphthalene-7-sulfonic acid | [CAS]
20191-62-2 | [Synonyms]
1-Hydroxynaphthalene-7-sulfonic acid
2-Naphthalenesulfonic acid, 8-hydroxy- | [Molecular Formula]
C10H8O4S | [MOL File]
20191-62-2.mol | [Molecular Weight]
224.23 |
| Hazard Information | Back Directory | [Chemical Properties]
1-Hydroxynaphthalene-7-sulfonic acid [20191-62-2]. (8-hydroxynaphthalene-2- sulfonic acid), C10H8O4S, Mr 224.2, is very soluble in water, and most of its metal salts are also readily soluble. It couples with diazotized 4- nitroaniline to give the 2,4-disazo compound. Nitration gives 2,4-dinitro-1-naphthol-7-sulfonic acid, which was known as Flavianic acid when used as a yellow dye for wool. | [Synthesis]
1-Naphthol is sulfonated with concentrated sulfuric acid at 130℃ to give a mixture of 2,7- and 4,7-disulfonic acids. This mixture is difficult to separate, but dilution with water and heating the resulting dilute sulfuric acid solution at 120℃ for 30 min result in selective desulfonation in the 2- and 4-positions.
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