90-20-0

Basic information

• Product Name: 1-Amino-8-hydroxynaphthalene-3,6-disulphonic acid
• Synonyms: 1-AMINO-8-NAPHTHOL-3,6-DISULFONIC ACID;4-AMINO-5-HYDROXY-2,7-NAPTHALENEDISULFONIC ACID;4-AMINO-5-HYDROXY-2,7-NAPHTHALENEDISULFONIC ACID;8-AMINO-1-NAPHTHOL-3,6-DISULFONIC ACID;1-Amino-8-naphthol-3,6-disulphonicacid;1-Naphthol-8-amino-3,6-disulfonicacid;4-amino-5-hydroxy-7-naphthalenedisulfonicacid;7-Naphthalenedisulfonicacid,4-amino-5-hydroxy-2
• CAS NO: 90-20-0
• Molecular Formula: C₁₀H₉NO₇S₂
• Molecular Weight: 319.31
• EINECS: 201-975-7
• Product Categories: Intermediates of Dyes and Pigments;OLED materials,pharm chemical,electronic
• Mol File: 90-20-0.mol
• Article Data: 8

Chemical Properties

• Melting Point: >300 °C(lit.)
• Appearance: /
• Density: 1.6832 (rough estimate)
• Refractive Index: 1.7640 (estimate)
• PKA: -0.95±0.40(Predicted)
• CAS DataBase Reference: 1-Amino-8-hydroxynaphthalene-3,6-disulphonic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 1-Amino-8-hydroxynaphthalene-3,6-disulphonic acid(90-20-0)
• EPA Substance Registry System: 1-Amino-8-hydroxynaphthalene-3,6-disulphonic acid(90-20-0)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 26-36
• WGK Germany: 3
• Hazardous Substances Data: 90-20-0(Hazardous Substances Data)

Usage

Uses

4-Amino-5-hydroxy-2,7-naphthalenedisulfonic Acid is useful for preparing reactive dyes.

Purification Methods

A slightly alkaline solution of Na2CO3 (ca 22g) in water (litmus) is added to a solution of 100g of the dry acid in 750mL of hot distilled water, followed by 5g of activated charcoal and 5g of Celite. The suspension is stirred for 10minutes and filtered by suction. The acid is then precipitated by adding ca 40mL of conc HCl (solution is blue to Congo Red), then filter it by suction through a shark skin filter circular sheet (or hardened filter paper) and wash it with 100mL of distilled water. The purification process is repeated. The acid is dried overnight in an oven at 60o and stored in a dark bottle The diethylamine salt has m 306-307o(dec, from aqueous EtOH). [Post & Moore Anal Chem 31 1872 1959]. [Beilstein 14 H 840, 14 I 758, 14 II 502, 14 III 2292, 14 IV 2824.]

InChI:InChI=1/C10H9NO7S2/c11-8-3-6(19(13,14)15)1-5-2-7(20(16,17)18)4-9(12)10(5)8/h1-4,12H,11H2,(H,13,14,15)(H,16,17,18)

Synthetic route

C10H8N2O6S2(2-)*2Na(1+) → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
With sulfuric acid; water at 90℃; for 5h;	65.86%

8-amino-naphthalene-1,3,6-trisulfonic acid (117-42-0) → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
With sodium hydroxide; water at 180 - 190℃; im offenen Gefaess;
With sodium hydroxide at 210℃; im geschlossenen Gefaess;
durch Alkalischmelze;
Stage #1: 8-amino-naphthalene-1,3,6-trisulfonic acid With sodium hydroxide under 6750.68 Torr; for 6h; Stage #2: With sulfuric acid In water for 2h; pH=2;

1,8-diamino-3,6-naphthalenedisulfonic acid (6362-11-4) + furan-2,3,5(4H)-trione pyridine (1:1) → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
at 200 - 210℃;

1,8-diamino-3,6-naphthalenedisulfonic acid (6362-11-4) → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
With sulfuric acid at 110 - 120℃;
With diluted alkali at 200 - 210℃; Kochen der erhaltenen Produkte nut verd. Schwefelsaeure oder Salzsaeure;

sulfuric acid (7664-93-9) + 1H-naphtho[1,8-de][1,2,3]triazine-5,8-disulfonic acid (6362-23-8) → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
at 170℃;

water (7732-18-5) + 1,1-dioxo-2H-1λ6-naphth[1,8-cd]isothiazole-4,7-disulfonic acid (408511-00-2) + sodium hydroxide → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
at 180℃; beim Schmelzen;

4-amino-5-chloro-naphthalene-2,7-disulfonic acid (784103-83-9) + potassium hydroxide → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
beim Verschmelzen;

2,7-naphthalenedisulfonic acid (92-41-1) → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: durch Nitrierung und Reduktion der entstandenen Dinitroverbindung 2: diluted alkali / 200 - 210 °C / Kochen der erhaltenen Produkte nut verd. Schwefelsaeure oder Salzsaeure View Scheme

naphthalene (91-20-3) → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: sulfuric acid / 100 - 165 °C 1.2: 10.75 h / 30 - 165 °C 2.1: nitric acid / 10 °C 3.1: iron / 60 °C 3.2: 80 - 90 °C 4.1: sodium hydroxide / 6 h / 6750.68 Torr 4.2: 2 h / pH 2 View Scheme

naphthalene-1,3,6-trisulfonic acid (86-66-8) → 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: nitric acid / 10 °C 2.1: iron / 60 °C 2.2: 80 - 90 °C 3.1: sodium hydroxide / 6 h / 6750.68 Torr 3.2: 2 h / pH 2 View Scheme

1-aminonaphthalene-3,6,8-trisulphonic acid trisodium salt → chromatotropic acid (148-25-4) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + C10H9NO7S2

Conditions	Yield
Stage #1: 1-aminonaphthalene-3,6,8-trisulphonic acid trisodium salt With sodium hydroxide In methanol at 180 - 200℃; under 21002.1 Torr; Stage #2: With sulfuric acid In methanol

naphthalene (91-20-3) → chromatotropic acid (148-25-4) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + C10H9NO7S2

Conditions	Yield
Multi-step reaction with 3 steps 1.1: sulfur trioxide; sulfuric acid / 65 - 150 °C 1.2: 40 °C 2.1: hydrogen / 170 °C / 150015 Torr 3.1: sodium hydroxide / methanol / 180 - 200 °C / 21002.1 Torr View Scheme

1,3,5-trichloro-2,4,6-triazine (108-77-0) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione (2944-29-8) + aniline (62-53-3) → C64H42Cl2N16O16S4

Conditions	Yield
Stage #1: 1,3,5-trichloro-2,4,6-triazine; 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid With sodium carbonate In water at 0 - 5℃; for 1h; pH=4 - 5; Stage #2: aniline In water at 25 - 30℃; for 3h; pH=5 - 6; Stage #3: 1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione Further stages;	91.3%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + C12H16N2O6S2 → C22H22N4O13S4

Conditions	Yield
Stage #1: C12H16N2O6S2 With hydrogenchloride; sodium nitrite In water Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid With sodium hydrogencarbonate In water for 3h; pH=3.5;	90%

1,3,5-trichloro-2,4,6-triazine (108-77-0) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 1-amino-2-sulfonic acid-4-(3-amino-2,4,6-trimethyl-5-sulfoamidophenyl)anthraquinone monosodium salt + sodium 7-aminonaphthalene-1,3,6-trisulphonate → C46H27ClN9O24S7(7-)*7Na(1+)

Conditions	Yield
Stage #1: 1,3,5-trichloro-2,4,6-triazine; 1-amino-2-sulfonic acid-4-(3-amino-2,4,6-trimethyl-5-sulfoamidophenyl)anthraquinone monosodium salt In water at 0 - 5℃; for 4h; pH=4- 6.5; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid In water at 28 - 35℃; pH=3.5 - 4; Stage #3: sodium 7-aminonaphthalene-1,3,6-trisulphonate Further stages;	86.4%

1,3,5-trichloro-2,4,6-triazine (108-77-0) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 1-amino-2-sulfonic acid-4-(3-amino-2,4,6-trimethyl-5-sulfoamidophenyl)anthraquinone monosodium salt + sodium 3‐aminonaphthalene‐1,5‐disulfonate → C46H28ClN9O21S6(6-)*6Na(1+)

Conditions	Yield
Stage #1: 1,3,5-trichloro-2,4,6-triazine; 1-amino-2-sulfonic acid-4-(3-amino-2,4,6-trimethyl-5-sulfoamidophenyl)anthraquinone monosodium salt In water at 0 - 5℃; for 4h; pH=4- 6.5; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid In water at 28 - 35℃; pH=3.5 - 4; Stage #3: sodium 3‐aminonaphthalene‐1,5‐disulfonate Further stages;	86.4%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 10-[(4'-bromomethyl)benzil]phenothiazine (246253-72-5) → 4-hydroxy-5-(4-phenothiazin-10-ylmethyl-benzylamino)-naphthalene-2,7-disulfonic acid (246253-74-7)

Conditions	Yield
With sodium acetate In water at 5 - 25℃; for 8h; Condensation;	85%

1,3,5-trichloro-2,4,6-triazine (108-77-0) + 2-amino-1-benzenesulfonic acid (88-21-1) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 1-amino-2-sulfonic acid-4-(3-amino-2,4,6-trimethyl-5-sulfoamidophenyl)anthraquinone monosodium salt → C42H27ClN9O18S5(5-)*5Na(1+)

Conditions	Yield
Stage #1: 1,3,5-trichloro-2,4,6-triazine; 1-amino-2-sulfonic acid-4-(3-amino-2,4,6-trimethyl-5-sulfoamidophenyl)anthraquinone monosodium salt In water at 0 - 5℃; for 4h; pH=4- 6.5; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid In water at 28 - 35℃; pH=3.5 - 4; Stage #3: 2-amino-1-benzenesulfonic acid Further stages;	84.23%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + bis(2-hydroxyethyl) 2-aminoterephthalate → C22H21N3O13S2

Conditions	Yield
Stage #1: bis(2-hydroxyethyl) 2-aminoterephthalate With hydrogenchloride; cis-nitrous acid In water at 5℃; for 5h; pH=8.5; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid With sodium carbonate for 1h; pH=8.5;	83.3%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 3-{4-[(E)-2-(2,4-Dichloro-phenyl)-vinyl]-phenyl}-2-mercapto-4-oxo-3,4-dihydro-quinazoline-6-diazonium → 5-Amino-3-(3-{4-[(E)-2-(2,4-dichloro-phenyl)-vinyl]-phenyl}-2-mercapto-4-oxo-3,4-dihydro-quinazolin-6-ylazo)-4-hydroxy-naphthalene-2,7-disulfonic acid

Conditions	Yield
With sodium carbonate; sodium chloride In water 1.) 0-5 deg C, 3 h; 2.) 60 deg C, 1 h;	83%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 3-aminobenzoyl fluoride → C24H15F2N5O9S2

Conditions	Yield
Stage #1: 3-aminobenzoyl fluoride With hydrogenchloride; sodium nitrite In water at 0 - 5℃; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid With ammonium chloride In water at 0 - 5℃; for 0.666667h; pH=5.5 - 6.5;	81%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 3-aminoterephthalic acid (10312-55-7) → C18H13N3O11S2

Conditions	Yield
Stage #1: 3-aminoterephthalic acid With hydrogenchloride; cis-nitrous acid In water at 10℃; for 5h; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid With sodium carbonate pH=7.5;	80.2%

2-(p-aminophenylsulfonyl)ethyl hydrogen sulfate (2494-89-5) + 1,3,5-trichloro-2,4,6-triazine (108-77-0) + 2-amino-1-benzenesulfonic acid (88-21-1) + 1-hydroxy-6-amino-3-naphthalenesulfonic acid (87-02-5) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 2,4-Diaminobenzenesulfonic acid (88-63-1) → C43H27ClN12O23S7(6-)*6Na(1+)

Conditions	Yield
Stage #1: 1,3,5-trichloro-2,4,6-triazine; 7-amino-4-hydroxy-2-naphthalenesulfonic acid With sodium hydroxide In water at 0 - 5℃; pH=5.6 - 6.5; Stage #2: With sodium carbonate In water at 3 - 5℃; for 5h; Stage #3: 2-(p-aminophenylsulfonyl)ethyl hydrogen sulfate; 2-amino-1-benzenesulfonic acid; 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid; 2,4-Diaminobenzenesulfonic acid Further stages;	77.1%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + p-toluenesulfonyl chloride (98-59-9) → N-(p-tosyl)-H-acid (6860-97-5)

Conditions	Yield
With sodium acetate; sodium hydroxide In water at 70℃; pH=3 - 6; Darkness;	77%

1,3,5-trichloro-2,4,6-triazine (108-77-0) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 1-(4'-sulfophenyl)-3-methylpyrazol-5-one (26878-11-5) + 2-amino-4-acetylaminobenzene sulfonic acid (88-64-2) + 2-amino-1,4-benzenedisulfonic acid monosodium Salt (24605-36-5) → C35H26ClN11O20S6

Conditions	Yield
Stage #1: 1,3,5-trichloro-2,4,6-triazine; 2-amino-1,4-benzenedisulfonic acid monosodium Salt In water at 0℃; for 3h; pH=6; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid In water at 35℃; for 4h; pH=4 - 5; Stage #3: 1-(4'-sulfophenyl)-3-methylpyrazol-5-one; 2-amino-4-acetylaminobenzene sulfonic acid Further stages;	58.7%

trifluoro-[1,3,5]triazine (675-14-9) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 1-(4'-sulfophenyl)-3-methylpyrazol-5-one (26878-11-5) + 2-amino-4-acetylaminobenzene sulfonic acid (88-64-2) + 2-amino-1,4-benzenedisulfonic acid monosodium Salt (24605-36-5) → C35H26FN11O20S6

Conditions	Yield
Stage #1: trifluoro-[1,3,5]triazine; 2-amino-1,4-benzenedisulfonic acid monosodium Salt In water at 0 - 5℃; pH=3 - 4; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid In water at 25℃; pH=4 - 5; Stage #3: 1-(4'-sulfophenyl)-3-methylpyrazol-5-one; 2-amino-4-acetylaminobenzene sulfonic acid Further stages;	52.1%

C4H4ClN4(1+)*Cl(1-) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → C18H13Cl2N9O7S2(2-)*2Na(1+)

Conditions	Yield
With sodium acetate; acetic acid In water for 0.5h;	49%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 4-Dodecyl-benzenediazonium → C28H35N3O7S2(2-)*2Na(1+)

Conditions	Yield
pH 5;	44%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 4,4'-Diaminostilbene dihydrochloride → C34H22N6O14S4(4-)*4Na(1+)

Conditions	Yield
Stage #1: 4,4'-Diaminostilbene dihydrochloride diazotization; Stage #2: 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid	38.5%

4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) + 4-Dodecyl-benzenediazonium → C28H35N3O7S2(2-)*2Na(1+)

Conditions	Yield
pH 9;	38%

phosgene (75-44-5) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 2-oxo-2,3-dihydro-naphth[1,8-de][1,3]oxazine-5,8-disulfonic acid (97629-54-4)

Conditions	Yield
With alkali

8-formylquinoline (38707-70-9) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 4-[8]quinolylmethylenamino-5-hydroxy-naphthalene-2,7-disulfonic acid

Conditions	Yield
With ethanol; water

1,3,5-trichloro-2,4,6-triazine (108-77-0) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 4-(4,6-dichloro-[1,3,5]triazin-2-ylamino)-5-hydroxy-naphthalene-2,7-disulfonic acid (7538-88-7)

Conditions	Yield
With sodium hydroxide
With sodium hydroxide In water at 0 - 5℃; for 1.5h;
With sodium hydroxide; disodium hydrogenphosphate In water at 0℃; for 2h; pH=3;

6-methoxyquinolin-8-amine (90-52-8) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 4-amino-5-hydroxy-3,6-bis-(6-methoxy-[8]quinolylazo)-naphthalene-2,7-disulfonic acid

3-acetoxy-2-naphthoyl chloride (53855-64-4) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 4-hydroxy-5-(3-hydroxy-[2]naphthoylamino)-naphthalene-2,7-disulfonic acid

Conditions	Yield
With alkali Verseifung der entstandenen Acetylverbindung mit verd. Natronlauge;

2-methoxy-benzenediazonium (17356-93-3) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 5-amino-4-hydroxy-3-(2-methoxy-phenylazo)-naphthalene-2,7-disulfonic acid

Conditions	Yield
With sodium carbonate

4-methylbenzene diazonium (57573-52-1) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 5-amino-4-hydroxy-3-p-tolylazo-naphthalene-2,7-disulfonic acid (84077-76-9)

Conditions	Yield
With sodium carbonate

o-Carboxybenzenediazonium (17333-86-7) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 2-(8-amino-1-hydroxy-3,6-disulfo-[2]naphthylazo)-benzoic acid (36429-86-4)

Conditions	Yield
With sodium carbonate

diazotiertes o-Phenetidin (24892-65-7) + 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (90-20-0) → 3-(2-ethoxy-phenylazo)-5-amino-4-hydroxy-naphthalene-2,7-disulfonic acid

Conditions	Yield
With sodium carbonate

Upstream product

• 91-20-3 naphthalene 
• 86-66-8 naphthalene-1,3,6-trisulfonic acid 
• 92-41-1 2,7-naphthalenedisulfonic acid 
• 784103-83-9 4-amino-5-chloro-naphthalene-2,7-disulfonic acid 
• 90947-32-3 1,8-dinitro-3,6-naphthalenedisulfonic acid 
• 6362-11-4 1,8-diamino-3,6-naphthalenedisulfonic acid 
• 117-42-0 8-amino-naphthalene-1,3,6-trisulfonic acid 
• 7732-18-5 water 
• 408511-00-2 1,1-dioxo-2H-1λ⁶-naphth[1,8-cd]isothiazole-4,7-disulfonic acid 
• 7664-93-9 sulfuric acid 
• 6362-23-8 1H-naphtho[1,8-de][1,2,3]triazine-5,8-disulfonic acid 

Downstream Products

• 16362-45-1 C₁₇H₁₂N₃O₇S₂^(3-)*3Na⁽¹⁺⁾ 
• 147656-23-3 C₁₆H₉BrN₃O₇S₂^(3-)*3Na⁽¹⁺⁾ 
• 17716-41-5 C₁₆H₉N₃O₁₀S₃^(4-)*4Na⁽¹⁺⁾ 
• 52172-47-1 1-amino-8-naphthol-7-(4-aminosulfophenyldiazinyl)-3,6-disulfonic acid 
• 1237680-63-5 4-(5-benzoyl-4-hydroxy-2-methoxyphenylazo)-5-hydroxy-2,7-naphthalenedisulphonic acid 
• 1268310-48-0 C₁₉H₁₃Cl₂N₅O₇S₂ 

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