51-19-4

Basic information

• Product Name: 2-AMINOPHENOL HYDROCHLORIDE
• Synonyms: 2-AMINOPHENOL HYDROCHLORIDE;2-AminophenolHCl;2-AMINOPHENOL HYDROCHLORIDE 98+%;2-Aminophenyl hydrochloride;Nsc165648;o-Aminophenyl hydrochloride;Phenol, o-amino-, hydrochloride;o-Aminophenol hydrochloride
• CAS NO: 51-19-4
• Molecular Formula: C₆H₈NO*Cl
• Molecular Weight: 145.59
• EINECS: 202-431-1
• Mol File: 51-19-4.mol
• Article Data: 6

Chemical Properties

• Melting Point: 207 °C
• Boiling Point: 234.5 °C at 760 mmHg
• Flash Point: 95.6 °C
• Appearance: /
• Density: 1.21 g/cm³
• Vapor Pressure: 0.0345mmHg at 25°C
• Refractive Index: 1.637
• Storage Temp.: 0-10°C
• Water Solubility: almost transparency
• Merck: 14,461
• CAS DataBase Reference: 2-AMINOPHENOL HYDROCHLORIDE(CAS DataBase Reference)
• NIST Chemistry Reference: 2-AMINOPHENOL HYDROCHLORIDE(51-19-4)
• EPA Substance Registry System: 2-AMINOPHENOL HYDROCHLORIDE(51-19-4)

Safety Data

• RTECS: SJ6069000
• Hazardous Substances Data: 51-19-4(Hazardous Substances Data)

Usage

General Description

2-Aminophenol hydrochloride is a chemical compound that consists of a hydrochloride salt of 2-aminophenol, which is a derivative of phenol. It is commonly used in the synthesis of pharmaceuticals and dyes as a raw material. 2-AMINOPHENOL HYDROCHLORIDE is known for its ability to undergo oxidation and reduction reactions, making it a valuable component in the production of various organic compounds. Additionally, it also exhibits antioxidant properties and can act as a stabilizer in certain chemical processes. Overall, 2-Aminophenol hydrochloride plays a crucial role in the manufacturing of a wide range of industrial products and is an important intermediate in organic synthesis.

InChI:InChI=1/C6H7NO/c7-5-3-1-2-4-6(5)8/h1-4,8H,7H2

Synthetic route

2-amino-phenol (95-55-6) → 2-aminophenol hydrochloride (51-19-4)

Conditions	Yield
With hydrogenchloride In methanol for 15h; Inert atmosphere;	90%
With hydrogenchloride In methanol at 20℃; for 15h; pH=2 - 5;
With hydrogenchloride In water

3-methyl-1,4-benzoxazin-2-one (7653-60-3) + ethanol (64-17-5) → 2-oxo-propionic acid ethyl ester (617-35-6) + 2-aminophenol hydrochloride (51-19-4)

Conditions	Yield
With hydrogenchloride for 0.25h; boiling water bath;

3-carboxyethylbenzoxazinone → α-ketoglutaric acid (328-50-7) + 2-aminophenol hydrochloride (51-19-4)

Conditions	Yield
With hydrogenchloride In ethanol for 0.25h; boiling water bath;

ethanol (64-17-5) + 3-phenyl-1,4-benzoxazin-2-one (27990-57-4) → phenylglyoxylic acid ethyl ester (1603-79-8) + 2-aminophenol hydrochloride (51-19-4)

Conditions	Yield
With hydrogenchloride for 0.25h; boiling water bath;

2-hydroxynitrobenzene (88-75-5) → 2-aminophenol hydrochloride (51-19-4)

Conditions	Yield
With hydrogenchloride; tin(ll) chloride In ethanol; water at 30℃; Rate constant; Mechanism; various concentration of HCl; different amounts of H2O as solvent;

2-chloro-4,8-dimethyl-quinoline (3913-17-5) + 2-aminophenol hydrochloride (51-19-4) → 2-(4,8-dimethylquinolin-2-ylamino)phenol hydrochloride (1436858-64-8)

Conditions	Yield
With hydrogenchloride In ethanol; water Heating;	92%

2-chloro-4,6-dimethylquinoline (3913-18-6) + 2-aminophenol hydrochloride (51-19-4) → 2-(4,6-dimethylquinolin-2-ylamino)phenolhydrochloride (1436858-58-0)

Conditions	Yield
With hydrogenchloride In ethanol; water Heating;	86%

2-aminophenol hydrochloride (51-19-4) + trichloro(o-phenylenedioxy)phosphorane (2007-97-8) → 2λ5,13'λ5-dispiro[benzo[1,3,2]dioxaphosphole-2,6'-dibenzo[d,d'][1,3,2,4]diazadiphospheto[2,1-b;4,3-b']bis[1,3,2]oxazaphosphole-13',2''-benzo[1,3,2]dioxaphosphole] (66258-52-4)

Conditions	Yield
	85%

ammonium thiocyanate (1147550-11-5) + 2-aminophenol hydrochloride (51-19-4) → 2-hydroxyphenylthiourea (1520-26-9)

Conditions	Yield
at 120 - 130℃; for 0.75h;	83%

Thiazole-2-carbaldehyde (10200-59-6) + 2-aminophenol hydrochloride (51-19-4) → (E)-2-((thiazol-2-ylmethylene)amino)phenol

Conditions	Yield
With triethylamine In toluene at 50℃; for 24h;	81.6%

2-chloro-4-methylquinoline (634-47-9) + 2-aminophenol hydrochloride (51-19-4) → 2-(4-methylquinolin-2-ylamino)phenol hydrochloride (1436858-53-5)

Conditions	Yield
With hydrogenchloride In ethanol; water Heating;	81%

2-aminophenol hydrochloride (51-19-4) + toluene-4-sulfonic acid (104-15-4) → 2-hydroxyphenylhydrazine p-toluenesulfonic acid salt

Conditions	Yield
Stage #1: 2-aminophenol hydrochloride With isopentyl nitrite In ethanol at -5 - 0℃; Stage #2: toluene-4-sulfonic acid With tin(ll) chloride In ethanol at 0 - 5℃; for 1h;	80%
With tin(ll) chloride; isopentyl nitrite 1) EtOH, 0 deg C, 2) EtOH, 0 deg C, 30 min; Yield given. Multistep reaction;

3-(3-phenoxybenzylamino)propionitrile (1038222-56-8) + 2-aminophenol hydrochloride (51-19-4) → 2-[2-(3-phenoxybenzylamino)ethyl]benzoxazole (1347646-76-7)

Conditions	Yield
at 190 - 200℃; Neat (no solvent); Sealed ampoule;	80%

3-phenoxyphenylacetonitrile (51632-29-2) + 2-aminophenol hydrochloride (51-19-4) → 2-(3-phenoxybenzyl)benzoxazole (1347646-70-1)

Conditions	Yield
at 190 - 200℃; Neat (no solvent); Sealed ampoule;	80%

2-aminophenol hydrochloride (51-19-4) → 2-hydroxyphenylhydrazine p-toluenesulfonic acid salt

Conditions	Yield
Stage #1: 2-aminophenol hydrochloride With isopentyl nitrite In ethanol at -5℃; Stage #2: With tin(IV) chloride; toluene-4-sulfonic acid In ethanol at -5℃; for 1h;	80%

C15H11NO (1347646-61-0) + 2-aminophenol hydrochloride (51-19-4) → 2-[(E)-2-(3-phenoxyphenyl)vinyl]benzoxazole (1062114-84-4)

Conditions	Yield
With hydroquinone at 190 - 200℃; Neat (no solvent); Sealed ampoule;	76%

3-phenoxybenzonitrile (50789-45-2) + 2-aminophenol hydrochloride (51-19-4) → 2-(3-phenoxyphenyl)benzoxazole (1152493-76-9)

Conditions	Yield
at 190 - 200℃; Neat (no solvent); Sealed ampoule;	74%

methanol (67-56-1) + 2-aminophenol hydrochloride (51-19-4) + copper + Phenylmalondialdehyd-natrium salz → Cu3((bis[(2-mercapto)anil] of phenylmalonaldehyde)-3H)2*methanol

Conditions	Yield
In methanol Electrolysis; in electrochem. cell contg. MeOH soln. of sodium phenylmalonaldehyde ando-aminophenol hydrochloride; Cu was a sol. anode; Pt was a cathode; LiC lO4 was a background electrolyte; electrolysis was performed at 20 mA and 20 V within 4 h at room temp.; the ppt. was filtered off, washed with hot methanol, and dried in a vac.oven at 150°C; elem. anal.;	70%

carbon disulfide (75-15-0) + 2-aminophenol hydrochloride (51-19-4) → benzo[d]oxazole-2-(3H)-thione (2382-96-9)

Conditions	Yield
With triethylamine In dichloromethane for 16h; Inert atmosphere; Reflux;	70%

2-aminophenol hydrochloride (51-19-4) + ethyl 4-amino-3-cyanopyrazolo<5,1-c><1,2,4>triazine-8-carboxylate (115423-03-5) → 9-ethoxycarbonyl-6-oxo-5,6-dihydropyrazolo<1',5':3,4><1,2,4>triazino<5,6-b><1,5>benzoxazepine (116507-25-6) + 9-ethoxycarbonyl-6-(o-hydroxyphenyl)aminopyrazolo<1',5':3,4><1,2,4>triazino<5,6-b><1,5>benzoxazepine (116507-28-9)

Conditions	Yield
In acetic acid for 5h; Heating;	A 22% B 68%

cis,trans-2,5-dimethoxytetrahydrofuran (696-59-3) + 2-aminophenol hydrochloride (51-19-4) → 2-(1H-pyrrol-1-yl)phenol (32277-91-1)

Conditions	Yield
With nicotinamide In 1,4-dioxane for 9h; Clauson-Kaas Synthesis; Reflux; Inert atmosphere;	67%

2-aminophenol hydrochloride (51-19-4) + 4-amino-3,8-bisethoxycarbonylpyrazolo<5,1-c><1,2,4>triazine (115423-04-6) → 9-ethoxycarbonyl-6-oxo-5,6-dihydropyrazolo<1',5':3,4><1,2,4>triazino<5,6-b><1,5>benzoxazepine (116507-25-6)

Conditions	Yield
In acetic acid for 5h; Heating;	66%

2-aminophenol hydrochloride (51-19-4) + 7-chloro-4-(2-cyano-2-hydroxyvinyl)tetrazolo<1,5-a>quinoxaline (153788-24-0) → 4-<2-(2-benzoxazolyl)-2-hydroxyvinyl>-7-chlorotetrazolo<1,5-a>quinoxaline

Conditions	Yield
With acetic acid for 2h; Heating;	65%

3-(3-phenoxyphenyl)-2-butenonitrile (1185760-64-8) + 2-aminophenol hydrochloride (51-19-4) → 2-[2-(3-phenoxyphenyl)propen-1-en-1-yl]benzoxazole (1347646-73-4)

Conditions	Yield
With hydroquinone at 190 - 200℃; Neat (no solvent); Sealed ampoule;	64%

2-methyl-2-(3-phenoxybenzoyloxy)propionitrile (1243274-72-7) + 2-aminophenol hydrochloride (51-19-4) → 1-(benzoxazol-2-yl)-1-methylethyl-3-phenoxybenzoate (1347646-79-0)

Conditions	Yield
at 190 - 200℃; Neat (no solvent); Sealed ampoule;	62%

3-(3-phenoxyphenyl)propanenitrile (1057676-70-6) + 2-aminophenol hydrochloride (51-19-4) → 2-[2-(3-phenoxyphenyl)ethyl]benzoxazole (1347646-75-6)

Conditions	Yield
at 190 - 200℃; Neat (no solvent); Sealed ampoule;	56%

2-aminophenol hydrochloride (51-19-4) + methyl 2-bromo-2-(3-bromophenyl)acetate (163339-67-1) → 2-(3-bromophenyl)-3,4-dihydro-2H-1,4-benzoxazin-3-one (244621-27-0)

Conditions	Yield
With sodium hydride In N,N-dimethyl-formamide at 20℃; for 24h; cyclocondensation;	55%

3-phenoxyphenylmethoxypropionitrile (1264878-02-5) + 2-aminophenol hydrochloride (51-19-4) → 2-{2-[(3-phenoxybenzyl)oxy]ethyl}benzoxazole (1347646-77-8)

Conditions	Yield
at 190 - 200℃; Neat (no solvent); Sealed ampoule;	51%

2-aminophenol hydrochloride (51-19-4) + ethyl 3-amino-4,5-diphenyl-1(H)-pyrrolo<2,3-c>pyridazine-2-carboxylate (141238-66-6) → 3,4-diphenyl-11-oxo-10,11-dihydro-12H-pyridazino<4',3':4,5>pyrrolo<3,2-b>benzoxazepine (141238-75-7)

Conditions	Yield
In acetic acid for 5h; Heating;	50%

copper diacetate (142-71-2) + 2-aminophenol hydrochloride (51-19-4) + Phenylmalondialdehyd-natrium salz → Cu3((bis[(2-mercapto)anil] of phenylmalonaldehyde)-3H)2

Conditions	Yield
With CH3COOH In 1,4-dioxane; methanol to a mixt. of methanol solns. of sodium phenylmalonaldehyde and o-aminophenol hydrochloride was added a 1:1 methanol-dioxane mixt. to dissolve the ppt. and then soln. of Cu-contg. compd. with 2-3 drops of AcOH to supress hydrolysis; the ppt. was filtered out, washed with methanol, and dried in a vac. oven at 120°C; elem. anal.;	50%

copper diacetate (142-71-2) + nitromalondialdehyde sodium salt (34461-00-2) + 2-aminophenol hydrochloride (51-19-4) → Cu3((bis[(2-mercapto)anil] of nitromalonaldehyde)-3H)2

Conditions	Yield
With CH3COOH In 1,4-dioxane; methanol to a mixt. of methanol solns. of sodium nitromalonaldehyde and o-aminophenol hydrochloride was added a 1:1 methanol-dioxane mixt. to dissolve the ppt. and then soln. of Cu-contg. compd. with 2-3 drops of AcOH to supress hydrolysis; the ppt. was filtered out, washed with methanol, and dried in a vac. oven at 120°C; elem. anal.;	50%

water (7732-18-5) + 2-aminophenol hydrochloride (51-19-4) + nickel diacetate (373-02-4, 14998-37-9, 33025-09-1, 94044-50-5, 98268-31-6) + Phenylmalondialdehyd-natrium salz → Ni3((bis[(2-mercapto)anil] of phenylmalonaldehyde)-3H)2*4H2O

Conditions	Yield
With CH3COOH; KOH In 1,4-dioxane; methanol to a mixt. of methanol solns. of sodium phenylmalonaldehyde and o-aminophenol hydrochloride was added a 1:1 methanol-dioxane mixt. to dissolve the ppt. and then soln. of Ni-contg. compd. with 2-3 drops of AcOH to supress hydrolysis; addn. of KOH in MeOH; the ppt. was filtered out, washed with methanol, and dried in a vac. oven at 120°C; elem. anal.;	50%

2-aminophenol hydrochloride (51-19-4) + urea (57-13-6) → 2-Benzoxazolinone (59-49-4) + n-(2-hydroxy-benzene)-urea (1196-72-1) + N-(o-hydroxyphenyl)biuret (63118-40-1)

Conditions	Yield
at 175℃; for 2h;	A 49% B 1% C 0.4%

3-phenyl-2-(3-phenoxyphenyl)acrylonitrile + 2-aminophenol hydrochloride (51-19-4) → 2-[2-phenyl-1-(3-phenoxyphenyl)vinyl]benzoxazole

Conditions	Yield
at 220 - 250℃; for 10h; Sealed tube;	36%

Upstream product

• 95-55-6 2-amino-phenol 
• 64-17-5 ethanol 
• 27990-57-4 3-phenyl-1,4-benzoxazin-2-one 
• 88-75-5 2-hydroxynitrobenzene 
• 7653-60-3 3-methyl-1,4-benzoxazin-2-one 
• 247571-62-6 3-carboxyethylbenzoxazinone 

Downstream Products

• 2382-96-9 benzo[d]oxazole-2-(3H)-thione 
• 5467-64-1 2-acetamidophenyl acetate 
• 614-80-2 2-(acetylamino)phenol 
• 833-50-1 2-phenylbenzo[d]oxazole 
• 835-71-2 2-(4-methylphenyl)-1,3-benzoxazole 
• 5465-16-7 N-(2-hydroxyphenyl)benzenesulfonamide 
• 95-21-6 2-methyl-1,3-benzoxazole 
• 6797-13-3 2-ethyl-1,3-benzoxazole 
• 71007-11-9 2-((Z)-2-Benzoylvinylamino)-phenol 
• 258-16-2 12H-benz[5,6][1,4]oxazino[2,3-b]quinoxaline 
• 88-75-5 2-hydroxynitrobenzene 
• 1347646-75-6 2-[2-(3-phenoxyphenyl)ethyl]benzoxazole 
• 1347646-77-8 2-{2-[(3-phenoxybenzyl)oxy]ethyl}benzoxazole 
• 1347646-76-7 2-[2-(3-phenoxybenzylamino)ethyl]benzoxazole 

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