98-37-3

Basic information

• Product Name: Benzenesulfonic acid,3-amino-4-hydroxy-
• Synonyms: 1-Phenol-4-sulfonicacid, 2-amino- (4CI);Metanilic acid, 4-hydroxy- (7CI,8CI);1-Amino-2-hydroxy-5-benzenesulfonic acid;1-Hydroxy-2-aminobenzene-4-sulfonicacid;2-Amino-1-phenol-4-sulfonic acid;2-Amino-4-sulfophenol;2-Aminophenol-4-sulfonic acid;2-Hydroxy-5-sulfoaniline;3-Amino-4-hydroxybenzenesulfonic acid;4-Hydroxy-3-aminobenzenesulfonic acid;NSC 1491;o-Aminophenol-p-sulfonic acid
• CAS NO: 98-37-3
• Molecular Formula: C₆H₇NO₄S
• Molecular Weight: 189.1891
• EINECS: 202-662-8
• Product Categories: Building Blocks;Chemical Synthesis;Organic Building Blocks;Sulfonic/Sulfinic Acids;Sulfur Compounds;Dye Intermediate;Intermediates of Dyes and Pigments
• Mol File: 98-37-3.mol
• Article Data: 10

Chemical Properties

• Melting Point: >300℃ (dec.)
• Boiling Point: 398.09℃[at 101 325 Pa]
• Appearance: brown crystals
• Density: 1.675 g/cm³
• Vapor Pressure: 0Pa at 25℃
• Refractive Index: 1.671
• Storage Temp.: Keep in dark place,Sealed in dry,Room Temperature
• PKA: -0.81±0.50(Predicted)
• Water Solubility: <0.1 g/100 mL at 21.5℃
• Stability: Stable. Incompatible with strong oxidizing agents, strong acids and strong bases.
• BRN: 514765
• CAS DataBase Reference: Benzenesulfonic acid,3-amino-4-hydroxy-(CAS DataBase Reference)
• NIST Chemistry Reference: Benzenesulfonic acid,3-amino-4-hydroxy-(98-37-3)
• EPA Substance Registry System: Benzenesulfonic acid,3-amino-4-hydroxy-(98-37-3)

Safety Data

• Hazard Codes: C:Corrosive
• Statements: R34:
• Safety Statements: S26:; S36/37/39:; S45:
• RIDADR: UN 2585 8/PG 3
• WGK Germany: 1
• HazardClass: 8
• PackingGroup: III
• Hazardous Substances Data: 98-37-3(Hazardous Substances Data)

Usage

Uses

3-Amino-4-hydroxybenzenesulfonic acid can be used to synthesize various heterocyclic Schiff bases for imaging applications. 3-Amino-4-hydroxybenzenesulfonic acid can also be used for comparative assessment in the Tetrahymena pyriformis growth inhibition assay.

General Description

Rhombic brown crystals.

Air & Water Reactions

2-Aminophenol-4-sulfonic acid may be sensitive to prolonged exposure to air. Insoluble in water.

Reactivity Profile

2-Aminophenol-4-sulfonic acid may react with strong oxidizers and mineral acids or bases.

Fire Hazard

Flash point data for 2-Aminophenol-4-sulfonic acid is not available, however 2-Aminophenol-4-sulfonic acid is probably combustible.

InChI:InChI=1/C6H7NO4S/c7-5-3-4(12(9,10)11)1-2-6(5)8/h1-3,8H,7H2,(H,9,10,11)

Synthetic route

3-nitro-4-chlorobenzenesulfonic acid (121-18-6) → 2-aminophenol-4-sulfonic acid (98-37-3)

Conditions	Yield
With sodium hydrogensulfite

4-hydroxy-3-nitrobenzene sulfonic acid (616-85-3) → 2-aminophenol-4-sulfonic acid (98-37-3)

Conditions	Yield
With hydrogenchloride; tin
With sodium sulfide

2-amino-phenol (95-55-6) → 2-aminophenol-4-sulfonic acid (98-37-3)

Conditions	Yield
With sulfuric acid

3-nitro-4-hydroxy-benzene-sulfonic acid-(1) → 2-aminophenol-4-sulfonic acid (98-37-3)

Conditions	Yield
With sodium sulfide; sodium hydroxide

sulfuric acid (7664-93-9) + 2-amino-phenol (95-55-6) → 2-aminophenol-4-sulfonic acid (98-37-3)

disodium-salt of/the/ 3-nitro-4-hydroxy-benzene-sulfonic acid-(1) → 2-aminophenol-4-sulfonic acid (98-37-3)

Conditions	Yield
With water; nickel at 70 - 100℃; Hydrogenation;

3-nitro-4-chlorobenzenesulfonic acid (121-18-6) + sodium hydrogensulfite → 2-aminophenol-4-sulfonic acid (98-37-3)

acetic anhydride (108-24-7) + 2-aminophenol-4-sulfonic acid (98-37-3) → 3-acetamido-4-acetoxybenzenesulfonic acid (123687-02-5)

Conditions	Yield
With sulfuric acid In methanol for 4h; Reflux;	97%
With sulfuric acid In methanol for 4h; Reflux;	97%
With pyridine

benzoyl chloride (98-88-4) + 2-aminophenol-4-sulfonic acid (98-37-3) → 3-benzoylamino-4-hydroxy-benzenesulfonic acid (23117-22-8)

Conditions	Yield
In water	96.3%

2-(trifluoromethyl)phenol (444-30-4) + 2-aminophenol-4-sulfonic acid (98-37-3) → 2-(2-hydroxyphenyl)benzo[d]oxazole-5-sulfonic acid (1276122-50-9)

Conditions	Yield
With sodium hydroxide In water at 80℃; for 2h;	92%

acetoacetamido (5977-14-0) + 2-aminophenol-4-sulfonic acid (98-37-3) → [Na(μ-1κO1,2κO2-((Z)-3-(2-(1-amino-1,3-dioxobutan-2-ylidene)hydrazineyl)-4-hydroxybenzenesulfonate))(H2O)3]2

Conditions	Yield
Stage #1: 2-aminophenol-4-sulfonic acid With water; sodium hydroxide; sodium nitrite at 0 - 5℃; for 0.0833333h; Stage #2: With hydrogenchloride; water at 0 - 5℃; for 0.5h; Stage #3: acetoacetamido With water; sodium acetate; sodium hydroxide In ethanol for 1h;	86%

2-amino-3-methylphenol (2835-97-4) + 2-aminophenol-4-sulfonic acid (98-37-3) → C13H10N2O5S

Conditions	Yield
With 3,4,5-trihydroxybenzoic acid; cobalt(II) acetate; sodium hydroxide In water at 25℃; under 3000.3 Torr; for 36h;	84%

2-aminophenol-4-sulfonic acid (98-37-3) + 3-methylbenzene-1,2-diol (488-17-5) → 2-hydroxy-4-methyl-3-oxo-3H-phenoxazine-8-sulfonic acid

Conditions	Yield
With 3,4,5-trihydroxybenzoic acid; oxygen; manganese(II) acetate; sodium hydroxide In water at 25℃; under 2250.23 Torr; for 0.416667h; pH=10; Sonication; Autoclave; Green chemistry; regioselective reaction;	72%

2-aminophenol-4-sulfonic acid (98-37-3) + 4-benzoyl-1,5-diphenyl-1H-3-pyrazole carboxylic acid chloride (188724-74-5) → 2-{[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}phenyl-4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carboxylate

Conditions	Yield
With triethylamine In benzene for 10h; Heating;	65%

4-chloro-benzoyl chloride (122-01-0) + 2-aminophenol-4-sulfonic acid (98-37-3) → 2-(4-chlorophenyl)benzo[d]oxazole-5-sulfonic acid

Conditions	Yield
Stage #1: 4-chloro-benzoyl chloride; 2-aminophenol-4-sulfonic acid at 180℃; for 14h; Stage #2: With thionyl chloride In chloroform Reflux;	55%

5-Aminosalicylic Acid (89-57-6) + 2-aminophenol-4-sulfonic acid (98-37-3) → 2-(5-amino-2-hydroxyphenyl)benzo[d]oxazole-5-sulfonic acid

Conditions	Yield
With polyphosphoric acid at 140 - 180℃;	54%

2,3-dihydroxybenzonitrile (67984-81-0) + 2-aminophenol-4-sulfonic acid (98-37-3) → 2-hydroxy-3-oxo-8-sulfo-3H-phenoxazine-4-carboxylic acid

Conditions	Yield
With 3,4,5-trihydroxybenzoic acid; water; oxygen; manganese(II) acetate; sodium hydroxide at 25℃; under 2250.23 Torr; for 0.916667h; pH=10; Sonication; Autoclave; Green chemistry; regioselective reaction;	52%

2-aminophenol-4-sulfonic acid (98-37-3) + 2-hydroxyresorcinol (87-66-1) → 2,3,4,6'-tetrahydroxy-3'-sulfoazobenzene (1367626-03-6)

Conditions	Yield
Stage #1: 2-aminophenol-4-sulfonic acid With hydrogenchloride In water at 0℃; Stage #2: With sodium nitrite In water at 0℃; for 2.5h; Stage #3: 2-hydroxyresorcinol With hydrogenchloride In water at 0℃; for 2.5h; pH=3;	47.8%

2-aminophenol-4-sulfonic acid (98-37-3) + acrolein (107-02-8) → 8-quinolinol-5-sulfonic acid (84-88-8)

Conditions	Yield
With hydrogenchloride In water at 100℃; for 1h; Skraup Quinoline Synthesis; Inert atmosphere;	39%

2-hydroxy-N-phenylnaphthalene-1-carboxamide (16670-63-6) + 2-aminophenol-4-sulfonic acid (98-37-3) → C23H16N3O6S(1-)*Na(1+) (1314111-39-1)

Conditions	Yield
Stage #1: 2-aminophenol-4-sulfonic acid With hydrogenchloride; sodium nitrite In water at -2 - 2℃; Stage #2: 2-hydroxy-N-phenylnaphthalene-1-carboxamide With sodium carbonate In water at 5 - 10℃; for 2h;	35.4%
Stage #1: 2-aminophenol-4-sulfonic acid With hydrogenchloride; sodium nitrite In water at -2 - 2℃; for 0.166667h; Stage #2: 2-hydroxy-N-phenylnaphthalene-1-carboxamide With sodium carbonate In water at 5 - 10℃; for 2h;	35%

2,3-oxynaphthoic acid phenylamide (92-77-3) + 2-aminophenol-4-sulfonic acid (98-37-3) → C26H20N3O7S(1-)

Conditions	Yield
Stage #1: 2-aminophenol-4-sulfonic acid With hydrogenchloride; sodium nitrite In water at -2 - 2℃; for 0.166667h; Stage #2: 2,3-oxynaphthoic acid phenylamide With sodium carbonate In water at 5 - 10℃; for 2h;	35.4%

oxiranyl-methanol (556-52-5) + 2-aminophenol-4-sulfonic acid (98-37-3) → 3-(2,3-dihydroxy-propylamino)-4-hydroxy-benzenesulfonic acid

Conditions	Yield
With sodium hydroxide

2-chloro-3,5-dinitro-benzenesulfonic acid (4515-26-8) + 2-aminophenol-4-sulfonic acid (98-37-3) → 4'-hydroxy-3,5-dinitro-2,3'-imino-bis-benzenesulfonic acid

potassium thioacyanate (333-20-0) + 2-aminophenol-4-sulfonic acid (98-37-3) → 2-thioxo-2,3-dihydro-benzoxazole-5-sulfonic acid (58089-26-2)

Conditions	Yield
With water anschliessend Erhitzen auf 150grad;

2-aminophenol-4-sulfonic acid (98-37-3) + 1-chloro-2,4-dinitro-benzene (97-00-7) → 3-(2,4-dinitro-anilino)-4-hydroxy-benzenesulfonic acid

Conditions	Yield
With sodium carbonate

2-aminophenol-4-sulfonic acid (98-37-3) + m-nitrobenzoic acid chloride (121-90-4) → 3-(3-amino-benzoylamino)-4-hydroxy-benzenesulfonic acid

Conditions	Yield
nachfolgend Reduktion;

2-aminophenol-4-sulfonic acid (98-37-3) → 2-hydroxy-5-sulfo-benzenediazonium-betaine (391859-81-7)

Conditions	Yield
Diazotization;
With water; cis-nitrous acid
With nitrous anhydride
With water; nitrous anhydride

2-aminophenol-4-sulfonic acid (98-37-3) → 2-oxo-2,3-dihydro-benzoxazole-5-sulfonic acid (33943-12-3)

Conditions	Yield
With sodium hydroxide

2-aminophenol-4-sulfonic acid (98-37-3) → 2-hydroxy-3-nitroaniline-5-sulfonic acid (96-93-5)

Conditions	Yield
With sulfuric acid; nitric acid at 0 - 3℃;

2-aminophenol-4-sulfonic acid (98-37-3) → 2-amino-1-hydroxybenzene-4-sulphonic acid-N-phenylamide (80-20-6)

Conditions	Yield
With phosphorus pentachloride Hinzufuegen von Anilin zu dem Reaktionsprodukt;

phenylglyoxylic acid ethyl ester (1603-79-8) + 2-aminophenol-4-sulfonic acid (98-37-3) → 2-oxo-3-phenyl-2H-benzo[1,4]oxazine-6-sulfonic acid (10502-39-3)

Conditions	Yield
With ammonium hydroxide In ethanol

1-hydroxy-4-naphthalenesulfonate (84-87-7) + 2-aminophenol-4-sulfonic acid (98-37-3) → C16H10N2O8S2(2-)*2Na(1+) (132281-56-2)

Conditions	Yield
With hydrogenchloride; sodium hydroxide; sodium carbonate; sodium chloride; sodium nitrite Multistep reaction;

sodium resorcinol-4-sulphonate (53819-36-6) + 2-aminophenol-4-sulfonic acid (98-37-3) → C12H8N2O9S2(2-)*2Na(1+) (132281-49-3)

Conditions	Yield
With hydrogenchloride; sodium hydroxide; sodium carbonate; sodium chloride; sodium nitrite Multistep reaction;

sodium 2-methylresorcinol-4-sulphonate (132281-58-4) + 2-aminophenol-4-sulfonic acid (98-37-3) → C13H10N2O9S2(2-)*2Na(1+) (132281-51-7)

Conditions	Yield
With hydrogenchloride; sodium hydroxide; sodium carbonate; sodium chloride; sodium nitrite 1b) 0 to 5 deg C, 2) 6 to 8 deg C, 1 d; Multistep reaction;

Upstream product

• 616-85-3 4-hydroxy-3-nitrobenzene sulfonic acid 
• 121-18-6 3-nitro-4-chlorobenzenesulfonic acid 
• 7664-93-9 sulfuric acid 
• 95-55-6 2-amino-phenol 

Downstream Products

• 123687-02-5 3-acetamido-4-acetoxybenzenesulfonic acid 
• 84-88-8 8-quinolinol-5-sulfonic acid 
• 1367626-03-6 2,3,4,6'-tetrahydroxy-3'-sulfoazobenzene 
• 1314111-39-1 C₂₃H₁₆N₃O₆S^(1-)*Na⁽¹⁺⁾ 
• 1276122-50-9 2-(2-hydroxyphenyl)benzo[d]oxazole-5-sulfonic acid 
• 1073969-04-6 C₁₂H₁₂N₄O₇S 
• 144344-16-1 2-Hydroxy-5-sulfo-benzol-(1-azo-5)-barbitursaeure 
• 1010082-89-9 2-[(1H-indol-3-ylmethylene)-amino]phenol-1-sulfonic acid 
• 861216-75-3 C₂₆H₁₉ClN₆O₁₂S₃ 
• 132281-51-7 C₁₃H₁₀N₂O₉S₂^(2-)*2Na⁽¹⁺⁾ 

Relevant articles and documents

One step hair coloring compositions using salts

A hair coloring composition comprising the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an amino phenol, a naphthol, a polyhydric phenol, a catechol and mixtures thereof; wherein the composition comprising one or more oxidative hair coloring agents further comprises al least one water soluble carbonate releasing salts; and optionally a water soluble ammonium salt, is described.

Transition metal complexes as dye forming catalysts in hair coloring compositions

A hair coloring composition comprising a first composition which comprises: (a) a dye forming transition metal salt or complex; which is first applied to the hair; and a second composition which comprises the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an aminophenol, a polyhydric phenol a catechol and mixtures thereof.

HAIR COLORING COMPOSITIONS

A hair coloring composition comprising: (a) from about 0.0003 moles (per 100 g of composition) to less than about 0.09 moles (per 100 g of composition) of an inorganic peroxygen oxidizing agent; and (b) an oxidative hair coloring agent; wherein the pH of each of (a) and (b) is in the range of from about 1 to about 6 and wherein the combined mixture of (a) and (b) has a pH in the range of from about 1 to about 6. The products can provide excellent hair coloring and in-use efficacy benefits including excellent initial color and good wash fastness in combination with reduced hair damage at low pH.