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| | 1,5-Naphthalenedisulfonic acid Basic information |
| | 1,5-Naphthalenedisulfonic acid Chemical Properties |
| Melting point | 242.5°C (rough estimate) | | Boiling point | 400.53°C (rough estimate) | | density | 1.7040 | | vapor pressure | 0Pa at 25℃ | | refractive index | 1.5630 (estimate) | | storage temp. | Store below +30°C. | | pka | -0.60±0.40(Predicted) | | color | Crystals or plates | | Water Solubility | 90.52g/L at 25℃ | | LogP | -0.94 | | CAS DataBase Reference | 81-04-9(CAS DataBase Reference) | | EPA Substance Registry System | 1,5-Naphthalenedisulfonic acid (81-04-9) |
| Hazard Codes | C | | Risk Statements | 34 | | Safety Statements | 22-24/25-45-36/37/39-26 | | RIDADR | UN 2585 | | WGK Germany | 1 | | HazardClass | 8 | | PackingGroup | III | | HS Code | 2904100090 | | Toxicity | LD50 orl-rat: 30 g/kg GISAAA 45(3),73,80 |
| | 1,5-Naphthalenedisulfonic acid Usage And Synthesis |
| Chemical Properties | Naphthalene-1,5-disulfonic acid [81-04-9]. Armstrong acid, C10H8O6S2, Mr 288.28, crystallizes as the tetrahydrate but dehydrates at 125 ℃ to give the anhydrous acid (mp 240 – 245℃). The disulfonic acid forms an anhydride when treated with oleum below 50℃. This anhydride reacts with ammonia to give a mixture of naphthalene-1,5-disulfonamide and naphthalene-1- sulfonamide-5-sulfonic acid. Treatment of the disodium salt of naphthalene-1,5-disulfonic acid with phosphorus pentachloride at 110℃ gives naphthalene-1,5-disulfonyl chloride (mp 184 ℃), which may also be prepared by chlorosulfonation of naphthalene. Reaction of an aqueous solution of naphthalene-1,5-disulfonic acid with bromide – bromate gives 1,5-dibromonaphthalene so readily that the yellow precipitate may be used to identify very low concentrations of the disulfonic acid. | | Uses | The disodium salt of naphthalene-1,5- disulfonic acid gives 1-hydroxynaphthalene-5- sulfonic acid or 1,5-dihydroxynaphthalene (see Section 3.3) by fusion processes. Further sulfonation of the disulfonated reaction mixture gives naphthalene-1,3,5-trisulfonic acid, and nitration leads to 1- and 2-nitronaphthalene-4,8-disulfonic acids as intermediates to the corresponding aminonaphthalene disulfonic acids. Naphthalene-1,5-disulfonic acid is an important stabilizer for diazo compounds. | | Definition | ChEBI: Naphthalene-1,5-disulfonic acid is a naphthalenesulfonic acid. | | Production Methods | Naphthalene is mixed with 20 % oleum at 20 – 35 C followed by gradual addition of 65 % oleum and further naphthalene alternately. After heating for 6 h at 55 C the reaction mixture is added to water, and the product is precipitated as the free acid by cooling or as the disodium salt by the addition of alkaline sodium sulfate. In each case, the isolated yield is ca. 53 %. The 1,6-disulfonic acid can be recovered from the filtrate. Higher yields of 4 have been reported for alternative processes; for example, solvent sulfonation with sulfur trioxide and chlorosulfonic acid in a solvent such as tetrachloroethylene [24] or sulfonation with oleum through a double screw-feed apparatus. | | Flammability and Explosibility | Not classified | | Safety Profile | Very low oral toxicity. Whenheated to decomposition it emits toxic fumes of SOx. Seealso SULFONATES. |
| | 1,5-Naphthalenedisulfonic acid Preparation Products And Raw materials |
| Raw materials | Sulfuric acid-->Naphthalene-->4-aminonaphthalene-1,5-disulphonic acid-->Chlorosulfonic acid | | Preparation Products | Direct Blue 71-->1,5-Dihydroxy naphthalene-->Reactive Red M-3BE-->trisodium 2-[[6-[(4,6-dichloro-1,3,5-triazin-2-yl)methylamino]-1-hydroxy-3-sulphonato-2-naphthyl]azo]naphthalene-1,5-disulphonate-->trisodium 2-[[6-[(4-amino-6-chloro-1,3,5-triazin-2-yl)methylamino]-1-hydroxy-3-sulphonato-2-naphthyl]azo]naphthalene-1,5-disulphonate-->NAPHTHALENE-1,7-DISULFONIC ACID-->1,6-Naphthalenedisulfonic acid-->Naphthalene-2-sulfonic acid-->Disodium 1,5-naphthalenedisulfonate |
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