2-Aminonaphthalene-1-sulfonic acid
- CAS No.
- 81-16-3
- Chemical Name:
- 2-Aminonaphthalene-1-sulfonic acid
- Synonyms
- TOBIAS ACID;Nsc5523;C10H8NO3S;TOBIAS ACI;TOBIAC ACID;SUPER J ACID;Tobiasacid,98%;Tourette's acid;Wln: L66J bswq cz;kyselinatobiasova
- CBNumber:
- CB1128987
- Molecular Formula:
- C10H9NO3S
- Molecular Weight:
- 223.25
- MDL Number:
- MFCD00003988
- MOL File:
- 81-16-3.mol
- MSDS File:
- SDS
- TDS File:
- TDS
| Product description | Number | Pack Size | Price |
| 2-Amino-1-naphthalenesulfonic Acid >98.0%(HPLC)(T) | A0343 | 25g | $48 |
| 2-Amino-1-naphthalenesulfonic Acid >98.0%(HPLC)(T) | A0343 | 500g | $408 |
| 2-Amino-1-naphthalenesulfonic acid ≥99%(Assay) | 31109 | 250G | $36.65 |
| 2-Amino-1-naphthalenesulfonic acid ≥99%(Assay) | 31109 | 1KG | $118.88 |
| 2-Amino-1-naphthalenesulfonic acid ≥99%(Assay) | 31109 | 2.5KG | $252.48 |
| More product size | |||
| Melting point | 180 °C |
|---|---|
| Boiling point | 220°C (rough estimate) |
| Density | 1.3588 (rough estimate) |
| refractive index | 1.5250 (estimate) |
| storage temp. | -20°C Freezer, Under inert atmosphere |
| solubility | DMSO (Slightly), Methanol (Slightly, Heated), Water (Slightly, Heated) |
| form | Solid |
| pka | pK1: 2.35 (25°C) |
| color | White to Off-White |
| Water Solubility | 4.083g/L(20 ºC) |
| Merck | 14,6406 |
| BRN | 613084 |
| InChI | 1S/C10H9NO3S/c11-9-6-5-7-3-1-2-4-8(7)10(9)15(12,13)14/h1-6H,11H2,(H,12,13,14) |
| InChIKey | GWIAAIUASRVOIA-UHFFFAOYSA-N |
| SMILES | Nc1ccc2ccccc2c1S(O)(=O)=O |
| CAS DataBase Reference | 81-16-3(CAS DataBase Reference) |
| EWG's Food Scores | 1 |
| FDA UNII | F9QKW1FCE0 |
| NIST Chemistry Reference | 2-Naphthylamine-1-sulfonic acid(81-16-3) |
| EPA Substance Registry System | 2-Amino-1-naphthalenesulfonic acid (81-16-3) |
| UNSPSC Code | 12352100 |
| NACRES | NA.22 |
SAFETY
Risk and Safety Statements
| Symbol(GHS) |  GHS07 |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Signal word | Warning | |||||||||
| Hazard statements | H320-H319 | |||||||||
| Precautionary statements | P264-P305+P351+P338+P337+P313-P280i-P305+P351+P338-P337+P313 | |||||||||
| PPE | Eyeshields, Gloves, type N95 (US) | |||||||||
| Risk Statements | 36/37/38-40 | |||||||||
| Safety Statements | 26-36/37/39 | |||||||||
| RIDADR | 2585 | |||||||||
| WGK Germany | 1 | |||||||||
| RTECS | QK1250000 | |||||||||
| TSCA | TSCA listed | |||||||||
| HS Code | 2921.45.9010 | |||||||||
| HazardClass | 8 | |||||||||
| PackingGroup | III | |||||||||
| Storage Class | 11 - Combustible Solids | |||||||||
| Hazardous Substances Data | 81-16-3(Hazardous Substances Data) | |||||||||
| NFPA 704 |
|
2-Aminonaphthalene-1-sulfonic acid price More Price(23)
| Manufacturer | Product number | Product description | CAS number | Packaging | Price | Updated | Buy |
|---|---|---|---|---|---|---|---|
| TCI Chemical | A0343 | 2-Amino-1-naphthalenesulfonic Acid >98.0%(HPLC)(T) | 81-16-3 | 25g | $48 | 2026-04-30 | Buy |
| TCI Chemical | A0343 | 2-Amino-1-naphthalenesulfonic Acid >98.0%(HPLC)(T) | 81-16-3 | 500g | $408 | 2026-04-30 | Buy |
| Chem-Impex | 31109 | 2-Amino-1-naphthalenesulfonic acid ≥99%(Assay) | 81-16-3 | 250G | $36.65 | 2026-05-19 | Buy |
| Chem-Impex | 31109 | 2-Amino-1-naphthalenesulfonic acid ≥99%(Assay) | 81-16-3 | 1KG | $118.88 | 2026-05-19 | Buy |
| Chem-Impex | 31109 | 2-Amino-1-naphthalenesulfonic acid ≥99%(Assay) | 81-16-3 | 2.5KG | $252.48 | 2026-05-19 | Buy |
2-Aminonaphthalene-1-sulfonic acid Chemical Properties,Uses,Production
Chemical Properties
Grey white to light pink powder. 2-Aminonaphthalene-1-sulfonic acid [81-16-3]. Tobias acid, C10H9NO3S, Mr 223.24, is sparingly soluble in water but the sodium salt is readily soluble. Coupling with diazo compounds takes place in the 1-position with elimination of the sulfonic acid group.
Uses
Azo dye intermediate, optical brighteners. Sulfonation with oleum gives 2-aminonaphthalene-1,5-disulfonic acid, which can be desulfonated to produce 2-aminonaphthalene-5- sulfonic acid. Tobias acid is used as a diazo component in acid dyes (e.g., C.I. Acid Yellow 19), red reactive dyes, and pigments such as the important Lithol Reds, [e.g., C.I. Pigment Red 49]. The free acid of C.I. Pigment Red 49 is also remarkably insoluble and can be used as a pigment.
Uses
2-Amino-1-naphthalenesulfonic acid has been used in the preparation of 2-(2-naphthylamino)benzoxazole by reacting with 2-chlorobenzoxazole.
Production Methods
2-Hydroxynaphthalene-1-sulfonic acid is heated with a mixture of ammonia and ammonium sulfite in an autoclave at 150 ℃ and 1 MPa for 30 h. The reaction mixture is added to a slurry of lime, and excess ammonia is driven off. Inorganic calcium salts are filtered off at 80℃, and the filtrate is acidified with hydrochloric acid at 40℃ to precipitate Tobias acid in 95 % yield. Care must be taken throughout the process to avoid desulfonation and formation of 2- naphthylamine.
General Description
2-Amino-1-naphthalenesulfonic acid is a manufacturing intermediate in the monosulfo monoazo color additive D&C Red No. 34 and its lakes.
Purification Methods
Crystallise the acid under nitrogen from boiling water and dry it in a steam oven [Bryson Trans Faraday Soc 47 522, 527 1951]. [Beilstein 14 III 2240, 14 IV 2792.]
2-Aminonaphthalene-1-sulfonic acid Preparation Products And Raw materials
Raw materials
1of3
Preparation Products
1of3
| Supplier | Tel | Country | ProdList | Advantage | |
|---|---|---|---|---|---|
| Hebei Chuanghai Biotechnology Co., Ltd | +8615350571055 | Sibel@chuanghaibio.com | China | 8738 | 58 |
| Hebei Chuanghai Biotechnology Co,.LTD | +86-86-13131129325 +8613131129325 | sales1@chuanghaibio.com | China | 5231 | 58 |
| Hebei Zhuanglai Chemical Trading Co Ltd | +86-16264648883 | niki@zlchemi.com | China | 7245 | 58 |
| career henan chemical co | +86-0371-86658258 +8613203830695 | sales@coreychem.com | China | 29815 | 58 |
| NINGBO INNO PHARMCHEM CO., LTD. | 13867897135 | sales@nbinno.com | CHINA | 923 | 58 |
| Xiamen AmoyChem Co., Ltd | +86-86-5926051114 +8615060885618 | sales@amoychem.com | China | 6366 | 58 |
| Shandong chuangyingchemical Co., Ltd. | 18853181302 | sale@chuangyingchem.com | CHINA | 5906 | 58 |
| CONIER CHEM AND PHARMA LIMITED | +8618523575427 | sales@conier.com | China | 49979 | 58 |
| Richest Group Ltd | 18017061086 | oled@richest-group.com | CHINA | 5600 | 58 |
| Fuxin Pharmaceutical | +86-021-021-50872116 +8613122107989 | contact@fuxinpharm.com | China | 10000 | 58 |
View Lastest Price from 2-Aminonaphthalene-1-sulfonic acid manufacturers
| Image | Update time | Product | Price | Min. Order | Purity | Supply Ability | Manufacturer | |
|---|---|---|---|---|---|---|---|---|
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2026-05-28 | 2-Aminonaphthalene-1-sulfonic acid
81-16-3
|
$2.00-5.00 | 1KG | 99% | 10000kg | Hebei Chuanghai Biotechnology Co,.LTD | |
 |
2026-03-20 | 2-Aminonaphthalene-1-sulfonic acid
81-16-3
|
1KG | 99% | 20 mt | Hebei Chuanghai Biotechnology Co., Ltd | ||
 |
2025-05-23 | 2-Aminonaphthalene-1-sulfonic acid
81-16-3
|
$45.00 | 1kg | 99% | 20 tons | Hebei Zhuanglai Chemical Trading Co Ltd |
-
- 2-Aminonaphthalene-1-sulfonic acid
81-16-3
- $2.00-5.00
- 99%
- Hebei Chuanghai Biotechnology Co,.LTD
-
- 2-Aminonaphthalene-1-sulfonic acid
81-16-3
- 99%
- Hebei Chuanghai Biotechnology Co., Ltd
-
- 2-Aminonaphthalene-1-sulfonic acid
81-16-3
- $45.00
- 99%
- Hebei Zhuanglai Chemical Trading Co Ltd
