137-09-7

Basic information

• Product Name: 2,4-Diaminophenol dihydrochloride
• Synonyms: 2,4-diamino-phenodihydrochloride;2,4-Diaminophenoldihydrochlor;acrol;dianol;2,4-DIAMINOPHENOL HCL;2 4-DIAMINOPHENOL DIHYDRATE 98%;2,4-DiaminophenolDihydrochloride,>98%;4-hydroxy-m-phenylenendiamine dihydrochloride
• CAS NO: 137-09-7
• Molecular Formula: C₆H₈N₂O*ClH
• Molecular Weight: 197.06
• EINECS: 205-279-4
• Product Categories: Industrial/Fine Chemicals
• Mol File: 137-09-7.mol
• Article Data: 2

Chemical Properties

• Melting Point: 222 °C (dec.)(lit.)
• Boiling Point: 347.4 °C at 760 mmHg
• Flash Point: 163.9 °C
• Appearance: Beige to gray-green/Crystalline Powder
• Density: 1.3457 (rough estimate)
• Vapor Pressure: 2.68E-05mmHg at 25°C
• Refractive Index: 1.5680 (estimate)
• Storage Temp.: Store below +30°C.
• Solubility: 275g/l
• Water Solubility: 27.5 g/100 mL (15 ºC)
• Stability: Stable. Incompatible with strong oxidizing agents, acids. Heat and light sensitive.
• Merck: 14,2983
• BRN: 3913728
• CAS DataBase Reference: 2,4-Diaminophenol dihydrochloride(CAS DataBase Reference)
• NIST Chemistry Reference: 2,4-Diaminophenol dihydrochloride(137-09-7)
• EPA Substance Registry System: 2,4-Diaminophenol dihydrochloride(137-09-7)

Safety Data

• Hazard Codes: Xn,Xi
• Statements: 22-36/37/38
• Safety Statements: 26-36
• RIDADR: UN 2811 6.1/PG 3
• WGK Germany: 3
• RTECS: SK7600000
• TSCA: Yes
• HazardClass: 6.1
• PackingGroup: III
• Hazardous Substances Data: 137-09-7(Hazardous Substances Data)

Usage

Chemical Properties

Grey white powder

Uses

Different sources of media describe the Uses of 137-09-7 differently. You can refer to the following data:
1. A trade name for diamidophenol, a developing agent for silver bromide gelatin emulsions that was introduced by Dr. Anderson in 1892. Amidol made negatives grayish black, with very little fog. It was favored over other alkaline developers because it could facilitate faster exposures.
2. 2,4-Diaminophenol dihydrochloride (Amidol) is used in the dye manufacturing industries and as a color accelerator in photographic developers. It is also employed as a pharmaceutical intermediate.
3. 2,4-Diaminophenol dihydrochloride (Amidol) was used in the dye manufacturing industries and as a color accelerator in photographic developers.

General Description

Grayish-white crystals.

Air & Water Reactions

Water soluble.

Reactivity Profile

Sensitive to heat and light. Incompatible with acids.

Fire Hazard

Flash point data for 2,4-Diaminophenol dihydrochloride are not available. 2,4-Diaminophenol dihydrochloride is probably combustible.

InChI:InChI=1/C6H8N2O.ClH/c7-4-1-2-6(9)5(8)3-4;/h1-3,9H,7-8H2;1H

Synthetic route

2,4-Dinitrophenol (51-28-5) → 2,4-diaminophenol dihydrochloride (137-09-7)

Conditions	Yield
With hydrogenchloride	91.5%
With hydrogenchloride; tin faellt aus der filtrieren Fluessigkeit durch konz.Salzsaeure;
With tin In hydrogenchloride Yield given;

4-chlorophenylacetic Acid (1878-66-6) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(4-chlorobenzyl)-5-aminobenzoxazole (381200-35-7)

Conditions	Yield
With PPA at 195 - 198℃; for 1.5h;	100%
With polyphosphoric acid at 200℃; for 1.5h;	75%
With PPA Heating;

2,4-diaminophenol dihydrochloride (137-09-7) + benzoic acid (65-85-0) → 5-amino-2-phenyl-1,3-benzoxazole (41373-37-9)

Conditions	Yield
PPA at 110 - 180℃; for 3h;	97%
With polyphosphoric acid at 110 - 180℃;	97%
With PPA at 110 - 180℃; for 4h;	63%

2,4-diaminophenol dihydrochloride (137-09-7) + 4-(1,1-dimethylethyl)benzoic acid (98-73-7) → 2-(4-tert-butylphenyl)benzo[d]oxazole-5-amine (293738-21-3)

Conditions	Yield
With polyphosphoric acid (PPA) at 180℃;	94%
With polyphosphoric acid (PPA) at 180℃;	94%
In various solvent(s) for 2.5h; Heating;

N-(Benzyloxycarbonyloxy)succinimide (13139-17-8) + 2,4-diaminophenol dihydrochloride (137-09-7) → dibenzyl 4-hydroxy-1,3-phenylenedicarbamate (1360875-58-6)

Conditions	Yield
With pyridine for 18h;	94%

2,4-diaminophenol dihydrochloride (137-09-7) + p-Toluic acid (99-94-5) → 2-(4-methylphenyl)-5-aminobenzoxazole (54995-50-5)

Conditions	Yield
With polyphosphoric acid at 170℃; for 1.5h;	92%
With polyphosphoric acid at 170 - 200℃;
With polyphosphoric acid at 160 - 220℃; for 0.1h;
With polyphosphoric acid at 160 - 190℃; for 3h;

2,4-diaminophenol dihydrochloride (137-09-7) + 2-(4-bromophenyl)-acetic acid (1878-68-8) → 2-(4-bromobenzyl)-5-aminobenzoxazole (1016836-17-1)

Conditions	Yield
With polyphosphoric acid at 200℃; for 1.5h;	89%
With PPA Heating;
With polyphosphoric acid at 160 - 220℃; for 0.1h;

4-Fluorobenzoic acid (456-22-4) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(4-fluorophenyl)benzo[d]oxazol-5-amine (116248-10-3)

Conditions	Yield
With polyphosphoric acid at 200℃; for 2h;	86%
With PPA for 2.5h; Heating;
In various solvent(s) for 2.5h; Heating;

2,4-diaminophenol dihydrochloride (137-09-7) + 3-chlorobenzoate (535-80-8) → 2-(3-chlorophenyl)benzo[d]oxazol-5-amine (54995-52-7)

Conditions	Yield
With polyphosphoric acid at 120 - 170℃;	86%

5,6-bis(2,6-diisopropylphenyloxy)-1,3-diiminoisoindoline + 2,4-diaminophenol dihydrochloride (137-09-7) → C102H113N7O7

Conditions	Yield
With N-ethyl-N,N-diisopropylamine at 120℃; for 5.5h;	85%

2,4-diaminophenol dihydrochloride (137-09-7) + 3,5-dimethoxybenzoic acid (1132-21-4) → 2-(3,5-dimethoxyphenyl)benzoxazol-5-amine

Conditions	Yield
With polyphosphoric acid at 80 - 95℃;	84%

2,4-diaminophenol dihydrochloride (137-09-7) + para-chlorobenzoic acid (74-11-3) → 2-(4-chlorophenyl)benzo[d]oxazol-5-amine (54995-51-6)

Conditions	Yield
With polyphosphoric acid at 200℃; for 1.5h;	82%
With polyphosphoric acid at 160 - 220℃; for 0.1h;

p-ethylbenzoic acid (619-64-7) + 2,4-diaminophenol dihydrochloride (137-09-7) → 5-amino-2-(4-ethylphenyl)-1,3-benzoxazole (116248-09-0)

Conditions	Yield
With polyphosphoric acid at 180℃; for 2h;	81%
With PPA for 2.5h; Condensation; Cyclization; Heating;
With PPA for 2.5h; Heating;

5-chloro-naphthalene-1-carboxylic acid (16650-52-5) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(5-chloronaphthalene-1-yl)benzo[d]oxazole-5-amine

Conditions	Yield
With polyphosphoric acid (PPA) at 180℃;	79%
With polyphosphoric acid (PPA) at 180℃;	79%

1-naphthalenecarboxylic acid (86-55-5) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(naphthalene-1-yl)benzo[d]oxazole-5-amine

Conditions	Yield
With polyphosphoric acid (PPA) at 180℃;	77%
With polyphosphoric acid (PPA) at 180℃;	77%

2,4-diaminophenol dihydrochloride (137-09-7) + meta-aminobenzoic acid (99-05-8) → 5-amino-2-(3'-aminophenyl)-benzoxazole (13676-48-7)

Conditions	Yield
With tin(II) chloride dihdyrate at 110 - 195℃; Inert atmosphere;	76.9%
With PPA at 150℃; for 12h;	67%
With PPA

2,4-diaminophenol dihydrochloride (137-09-7) + naphthalene-2-carboxylate (93-09-4) → 2-(naphthalene-2-yl)-benzo[d]oxazole-5-amine (95888-12-3)

Conditions	Yield
With polyphosphoric acid (PPA) at 180℃;	75%
With polyphosphoric acid (PPA) at 180℃;	75%
at 180℃; for 3h;	63%

2,4-diaminophenol dihydrochloride (137-09-7) + p-Fluorophenylacetic acid (405-50-5) → 2-(4-fluorobenzyl)-5-aminobenzoxazole (959958-63-5)

Conditions	Yield
With polyphosphoric acid at 200℃; for 1.5h;	72%
With PPA Heating;
With polyphosphoric acid at 160 - 220℃; for 0.1h;

di-tert-butyl dicarbonate (24424-99-5) + 2,4-diaminophenol dihydrochloride (137-09-7) → di-tert-butyl (4-hydroxy-1,3-phenylene)dicarbamate

Conditions	Yield
With sodium hydrogencarbonate In tetrahydrofuran; water at 20℃; for 48h;	68%

phenylacetic acid (103-82-2) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-benzyl-5-aminobenzoxazole (313527-44-5)

Conditions	Yield
With PPA at 150 - 160℃; for 2.5h;	66%
With PPA at 210℃; for 2.5h;	65%
With polyphosphoric acid at 180℃; for 1.5h;	61%

4-tolylacetic acid (622-47-9) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(4-methylbenzyl)-5-aminobenzoxazole (959958-62-4)

Conditions	Yield
With polyphosphoric acid at 180℃; for 1.5h;	61%
With PPA Heating;
With polyphosphoric acid at 160 - 220℃; for 0.1h;

4-Bromobenzoic acid (586-76-5) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(4-bromophenyl)-5-aminobenzoxazole (54995-56-1)

Conditions	Yield
With polyphosphoric acid at 200℃; for 2.5h;	60%
With polyphosphoric acid at 160 - 220℃; for 0.1h;

5,6-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)isoindoline-1,3-diimine + 2,4-diaminophenol dihydrochloride (137-09-7) → C72H101N7O25

Conditions	Yield
With N-ethyl-N,N-diisopropylamine at 120℃; for 5h;	60%

isoindole-1,3-diylidenediamine (160956-25-2, 160956-26-3, 160956-27-4, 160956-28-5, 160956-29-6) + 2,4-diaminophenol dihydrochloride (137-09-7) → C22H16N6O (1301248-13-4)

Conditions	Yield
With triethylamine In ethanol at 0℃; for 24h; Darkness;	53%

5-Aminosalicylic Acid (89-57-6) + 2,4-diaminophenol dihydrochloride (137-09-7) → 5-amino-2-(5'-amino-2'-hydroxyphenyl)benzoxazole

Conditions	Yield
With PPA for 15h; Heating;	52%
With PPA at 150℃; for 12h;	27%

2-aminobenzothiazole-6-carboxylic acid (93-85-6) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(2-aminobenzo[d]thiazol-6-yl)benzo[d]oxazol-5-amine

Conditions	Yield
With Eaton′s Reagent for 8h; Reflux;	51%

benzothiazole-6-carboxylic acid (3622-35-3) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(benzo[d]thiazol-6-yl)benzo[d]oxazol-5-amine

Conditions	Yield
With Eaton′s Reagent for 8h; Reflux;	49%

di-tert-butyl dicarbonate (24424-99-5) + 3-hydroxy phenylacetylene (10401-11-3) + 2,4-diaminophenol dihydrochloride (137-09-7) + phenyl chloroformate (1885-14-9) → C15H12N2O3 (1135615-11-0)

Conditions	Yield
Stage #1: di-tert-butyl dicarbonate; 2,4-diaminophenol dihydrochloride With potassium carbonate In water at 20℃; Cooling with ice; Stage #2: phenyl chloroformate With pyridine In 1-methyl-pyrrolidin-2-one at 20℃; Cooling with ice; Stage #3: 3-hydroxy phenylacetylene	45%

benzothiazole-6-carboxylic acid (3622-35-3) + 2,4-diaminophenol dihydrochloride (137-09-7) → 2-(benzo[d]thiazol-5-yl)benzo[d]oxazole

Conditions	Yield
With Eaton′s Reagent for 8h; Reflux;	44%

2,4-diaminophenol dihydrochloride (137-09-7) + 4-methoxybenzoic acid (100-09-4) → 2-(4-methoxyphenyl)benzo[d]oxazol-5-amine

Conditions	Yield
With polyphosphoric acid at 120 - 180℃; for 2.5h;	42%
With polyphosphoric acid at 120℃; for 2h;	41%

Upstream product

• 51-28-5 2,4-Dinitrophenol 

Downstream Products

• 92959-62-1 2,4-diacetamidophenyl acetate 
• 120-83-2 2,4-dichlorophenol 
• 408510-82-7 4-(2,4-dinitro-phenoxy)-m-phenylenediamine 
• 13676-48-7 5-amino-2-(3'-aminophenyl)-benzoxazole 
• 13676-47-6 5-amino-2-(4'-aminophenyl)-benzoxazole 
• 116248-10-3 2-(4-fluorophenyl)benzo[d]oxazol-5-amine 
• 116248-11-4 2-(4-dimethylamino-phenyl)-benzoxazol-5-ylamine 
• 313527-44-5 2-benzyl-5-aminobenzoxazole 
• 1005003-21-3 5-amino-2-(2'-hydroxy-4'-methylphenyl)benzoxazole 
• 1352918-31-0 5-[4''-(5'''-aminobenzo[d]oxazol-2'''-yl)-2''-fluorophenyl]-2'-deoxyuridine 
• 1352918-39-8 5-[4''-(5'''-aminobenzo[d]oxazol-2'''-yl)-2''-fluorophenyl]-2'-deoxyuridine 5'-O-triphosphate 
• 1352918-23-0 5-amino-2-(4'-pinacolatoboronyl-3'-fluorophenyl)-1,3-benzoxazole 
• 1159548-85-2 5-amino-2-(4'-bromo-3'-fluorophenyl)-1,3-benzoxazole 

Relevant articles and documents

Synthesis of Substituted Dibenzophospholes. Part 5. Synthesis of Intermediates for 4- and 6-Aryl Substituents

6-Iodo-5-methoxy-8-methyl-1,2,3,4-tetrahydro-1,4-ethanonaphthalene was prepared from the Diels-Alder adduct of benzoquinone and cyclohexadiene.Diels-Alder condensation of 2-acetamimido-benzoquinone and 2-iodobenzoquinone (convenient, new syntheses of both quinones are described) with 2-methylcyclohexa-1,3-diene led to mixtures of adducts; the major adduct from the iodoquinone was isolated and found by X-ray analysis to have the methyl and iodo substituents at the 2- and 7-positions, respectively, of the 1,4-ethanonaphthalene skeleton.Addition of 2-acetamidobenzoquinone to mentha-2,6,8(9)-triene derived from (-)-carvone gave two regioisomers (structures determined by n.m.r. spectroscopy).In a smooth 4-step synthesis from 6,6-dimethylfulvene and benzoquinone, 6-iodo-9-syn-isopropyl-5,8-dimethoxy-1,2,3,4-tetrahydro-1,4-methanonaphthalene was prepared and its stucture confirmed by X-ray analysis.