55-55-0

Basic information

• Product Name: 4-Methylaminophenol sulfate
• Synonyms: METOL;METOL(TM);METHOL;BIS-(N-METHYL-4-HYDROXYANILINIUM) SULFATE;ARMOL;ELON;ECOL(R);GENOL
• CAS NO: 55-55-0
• Molecular Formula: 2C₇H₉NO*H₂O₄S
• Molecular Weight: 221.23
• EINECS: 200-237-1
• Product Categories: Industrial/Fine Chemicals;Pharmaceutical Raw Materials
• Mol File: 55-55-0.mol
• Article Data: 1

Chemical Properties

• Melting Point: 260 °C (dec.)(lit.)
• Boiling Point: 262.7 °C at 760 mmHg
• Flash Point: 148.6 °C
• Appearance: white to faintly beige/Powder
• Density: 1.577
• Refractive Index: 1.6510 (estimate)
• Storage Temp.: −20°C
• Solubility: H2O: 50 mg/mL, clear
• Water Solubility: 50 g/L (20 ºC)
• Sensitive: Air Sensitive
• Stability: Stability Combustible. Incompatible with strong oxidizing agents, acids, acid halides.
• Merck: 14,6017
• BRN: 3919382
• CAS DataBase Reference: 4-Methylaminophenol sulfate(CAS DataBase Reference)
• NIST Chemistry Reference: 4-Methylaminophenol sulfate(55-55-0)
• EPA Substance Registry System: 4-Methylaminophenol sulfate(55-55-0)

Safety Data

• Hazard Codes: Xn,N
• Statements: 22-43-48/22-50/53
• Safety Statements: 36/37-46-60-61
• RIDADR: UN 3077 9/PG 3
• WGK Germany: 3
• RTECS: SL8650000
• F: 8
• TSCA: Yes
• HazardClass: 6.1
• PackingGroup: III
• Hazardous Substances Data: 55-55-0(Hazardous Substances Data)

Usage

Description

Metol is contained in black-and-white film developers and caused contact dermatitis in photographers.

Chemical Properties

White crystalline powder

Uses

Different sources of media describe the Uses of 55-55-0 differently. You can refer to the following data:
1. Photographic developer; dyeing furs.
2. Metol is a black-and-white photographic developer; dyeing furs; as pigment in hair dyes.
3. 4-(Methylamino)phenol sulfate is a photographic developer used in black and white photography. It is also used as tone developers in developing agents. Further, it is used in oxidative hair dye formulations.
4. 4-methylaminophenol sulfate is used as a photographic developer and fur dye.

Definition

ChEBI: The sulfate salt of 4-methylaminophenol.

General Description

Off-white crystalline solid. Sensitive to light.

Air & Water Reactions

Water soluble.

Hazard

Eye and skin irritant.

Fire Hazard

Flash point data for 4-Methylaminophenol sulfate are not available but 4-Methylaminophenol sulfate is probably combustible.

Purification Methods

Crystallise this photographic developer from H2O (needles m 250-260o) (its solubility is 5% at 20o and 17% at 100o) or MeOH. It is used for determining Ag. [Palit et al. Indian J Chem, Sect B 28 64 1989.]

InChI:InChI=1/2C7H9NO.H2O4S/c2*1-8-6-2-4-7(9)5-3-6;1-5(2,3)4/h2*2-5,8-9H,1H3;(H2,1,2,3,4)/p-2

Synthetic route

acetic acid-(4-benzylidenamino-phenyl ester) (13031-47-5) + dimethyl sulfate (77-78-1) → 4-(methylamino)phenol sulphate (55-55-0)

Conditions	Yield
at 135℃; Zersetzen mit Wasser und Kochen mit konz.Salzsaeure;

p-aminophenol hydrochloride (51-78-5) + dimethyl sulfate (77-78-1) → 4-(methylamino)phenol sulphate (55-55-0)

Conditions	Yield
Yield given. Multistep reaction;

4-(methylamino)phenol sulphate (55-55-0) + tert-butyldimethylsilyl chloride (18162-48-6) → 4-((tert-butyldimethylsilyl)oxy)-N-methylaniline (90446-71-2)

Conditions	Yield
With sodium hydride In tetrahydrofuran at -78℃;	97%

formaldehyd (50-00-0) + 4-(methylamino)phenol sulphate (55-55-0) + butanone (78-93-3) → 1,3,4-trimethyl-6-hydroxyquinolinium perchlorate

Conditions	Yield
With perchloric acid In nitrobenzene; butan-1-ol at 95℃; for 7h;	79.8%

acetic anhydride (108-24-7) + 4-(methylamino)phenol sulphate (55-55-0) → N-methyl-(4-acetamido)phenol (579-58-8)

Conditions	Yield
In water for 0.0333333h; Heating;	73%

4-(methylamino)phenol sulphate (55-55-0) + 1,1'-carbonyldiimidazole (530-62-1) + (3R,4R)-pyrrolidine-3,4-diol (186393-31-7) → (3R,4R)-3,4-Dihydroxy-pyrrolidine-1-carboxylic acid (4-hydroxy-phenyl)-methyl-amide

Conditions	Yield
Multistep reaction;	67%

pyrrolidin-3-ol (40499-83-0) + 4-(methylamino)phenol sulphate (55-55-0) + 1,1'-carbonyldiimidazole (530-62-1) → 3-hydroxy-pyrrolidine-1-carboxylic acid (4-hydroxy-phenyl)-methyl-amide

Conditions	Yield
Multistep reaction;	63%

4-(methylamino)phenol sulphate (55-55-0) + (3R)-pyrrolidinol (40499-83-0, 83220-72-8, 100243-39-8, 2799-21-5) + 1,1'-carbonyldiimidazole (530-62-1) → (R)-3-Hydroxy-pyrrolidine-1-carboxylic acid (4-hydroxy-phenyl)-methyl-amide

Conditions	Yield
Multistep reaction;	60%

pyrrolidin-3-one (96-42-4) + 4-(methylamino)phenol sulphate (55-55-0) + 1,1'-carbonyldiimidazole (530-62-1) → 3-oxo-pyrrolidine-1-carboxylic acid (4-hydroxy-phenyl)-methyl-amide

Conditions	Yield
Multistep reaction;	48%

C23H32ClN2Si(1+) + 4-(methylamino)phenol sulphate (55-55-0) → C30H40N3OSi(1+)

Conditions	Yield
Stage #1: 4-(methylamino)phenol sulphate With triethylamine In acetonitrile for 0.5h; Stage #2: C23H32ClN2Si(1+) In acetonitrile for 0.0833333h;	29%

benzothiazole-6-carboxylic acid (3622-35-3) + 4-(methylamino)phenol sulphate (55-55-0) → N-(4-hydroxyphenyl)-N-methylbenzo[d]thiazole-6-carboxamide (1354404-59-3)

Conditions	Yield
Stage #1: benzothiazole-6-carboxylic acid With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In N,N-dimethyl-formamide at 20℃; for 0.333333h; Stage #2: 4-(methylamino)phenol sulphate With triethylamine In N,N-dimethyl-formamide at 20℃; for 120h;	26%

4,7-dichloroquinoline (86-98-6) + 4-(methylamino)phenol sulphate (55-55-0) + phenol (108-95-2) → 4-[(7-chloro-quinolin-4-yl)-methyl-amino]-phenol (92873-40-0)

4,5-methylenedioxy-2-nitrobenzoyl chloride (50425-29-1) + 4-(methylamino)phenol sulphate (55-55-0) → 6-nitro-benzo[1,3]dioxole-5-carboxylic acid-(4-hydroxy-N-methyl-anilide) (109411-55-4)

Conditions	Yield
With 1,4-dioxane; water; sodium hydrogencarbonate

4-(methylamino)phenol sulphate (55-55-0) + 2-chloro-ethanol (107-07-3) → 2-(4-hydroxy-N-methyl-anilino)-ethanol (13278-69-8)

4-(methylamino)phenol sulphate (55-55-0) → (S)-3-Hydroxy-pyrrolidine-1-carboxylic acid (4-hydroxy-phenyl)-methyl-amide

Conditions	Yield
Multi-step reaction with 5 steps 1: 97 percent / NaH / tetrahydrofuran / -78 °C 2: 91 percent / tetrahydrofuran / 20 °C 3: 92 percent / acetonitrile / 20 °C 4: 81 percent / Et3N / CH2Cl2 / 20 °C 5: 89 percent / TBAF / tetrahydrofuran / 20 °C View Scheme

4-(methylamino)phenol sulphate (55-55-0) → imidazole-1-carboxylic acid [4-(tert-butyl-dimethyl-silanyloxy)-phenyl]-methyl-amide (872168-52-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: 97 percent / NaH / tetrahydrofuran / -78 °C 2: 91 percent / tetrahydrofuran / 20 °C View Scheme

4-(methylamino)phenol sulphate (55-55-0) → 3-hydroxy-pyrrolidine-1-carboxylic acid [4-(tert-butyl-dimethyl-silanyloxy)-phenyl]-methyl-amide (872168-54-2)

Conditions	Yield
Multi-step reaction with 4 steps 1: 97 percent / NaH / tetrahydrofuran / -78 °C 2: 91 percent / tetrahydrofuran / 20 °C 3: 92 percent / acetonitrile / 20 °C 4: 81 percent / Et3N / CH2Cl2 / 20 °C View Scheme

4-(methylamino)phenol sulphate (55-55-0) → 3-{[4-(tert-butyl-dimethyl-silanyloxy)-phenyl]-methyl-carbamoyl}-1-methyl-3H-imidazol-1-ium; iodide

Conditions	Yield
Multi-step reaction with 3 steps 1: 97 percent / NaH / tetrahydrofuran / -78 °C 2: 91 percent / tetrahydrofuran / 20 °C 3: 92 percent / acetonitrile / 20 °C View Scheme

4-(methylamino)phenol sulphate (55-55-0) → N,N'-bis-(2-hydroxy-ethyl)-N,N'-dimethyl-4,4'-heptanediyldioxy-di-aniline (120548-05-2)

Conditions	Yield
Multi-step reaction with 2 steps 2: ethanolic NaOH View Scheme

4-(methylamino)phenol sulphate (55-55-0) → 6-amino-benzo[1,3]dioxole-5-carboxylic acid-(4-benzoyloxy-N-methyl-anilide) (115121-74-9)

Conditions	Yield
Multi-step reaction with 3 steps 1: dioxane; sodium hydrogencarbonate; water 2: aqueous alkaline solution 3: palladium/charcoal; ethanol / 70 °C / Hydrogenation View Scheme

4-(methylamino)phenol sulphate (55-55-0) → 6-nitro-benzo[1,3]dioxole-5-carboxylic acid-(4-benzoyloxy-N-methyl-anilide) (857388-87-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: dioxane; sodium hydrogencarbonate; water 2: aqueous alkaline solution View Scheme

4-(methylamino)phenol sulphate (55-55-0) → 6-benzylidenamino-benzo[1,3]dioxole-5-carboxylic acid-(4-benzoyloxy-N-methyl-anilide) (121446-20-6)

Conditions	Yield
Multi-step reaction with 4 steps 1: dioxane; sodium hydrogencarbonate; water 2: aqueous alkaline solution 3: palladium/charcoal; ethanol / 70 °C / Hydrogenation 4: ethanol View Scheme

ethacridine lactate (1837-57-6) + 4-(methylamino)phenol sulphate (55-55-0) → 2C7H7NO*C15H15N3O

Conditions	Yield
With potassium iodate In methanol pH=3.1; aq. buffer;

4-(methylamino)phenol sulphate (55-55-0) → C22H19N3O2S (1454918-37-6)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / N,N-dimethyl-formamide / 0.33 h / 20 °C 1.2: 120 h / 20 °C 2.1: caesium carbonate; potassium iodide / acetone / 21 h / Reflux View Scheme

4-(methylamino)phenol sulphate (55-55-0) → N-(4-(benzo[d]oxazol-2-ylmethoxy)phenyl)-N-methylisonicotinamide (1454918-38-7)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / N,N-dimethyl-formamide / 0.33 h / 20 °C 1.2: 120 h / 20 °C 2.1: caesium carbonate; potassium iodide / acetone / 21 h / Reflux View Scheme

Upstream product

• 51-78-5 p-aminophenol hydrochloride 
• 77-78-1 dimethyl sulfate 
• 13031-47-5 acetic acid-(4-benzylidenamino-phenyl ester) 

Downstream Products

• 109411-55-4 6-nitro-benzo[1,3]dioxole-5-carboxylic acid-(4-hydroxy-N-methyl-anilide) 
• 90446-71-2 4-[(tert-butyldimethylsilyl)oxy]-N-methylaniline 
• 1454918-37-6 C₂₂H₁₉N₃O₂S 
• 1354404-59-3 N-(4-hydroxyphenyl)-N-methylbenzo[d]thiazole-6-carboxamide 
• 121446-20-6 6-benzylidenamino-benzo[1,3]dioxole-5-carboxylic acid-(4-benzoyloxy-N-methyl-anilide) 
• 857388-87-5 6-nitro-benzo[1,3]dioxole-5-carboxylic acid-(4-benzoyloxy-N-methyl-anilide) 
• 115121-74-9 6-amino-benzo[1,3]dioxole-5-carboxylic acid-(4-benzoyloxy-N-methyl-anilide) 
• 120548-05-2 N,N'-bis-(2-hydroxy-ethyl)-N,N'-dimethyl-4,4'-heptanediyldioxy-di-aniline 
• 872168-54-2 3-hydroxy-pyrrolidine-1-carboxylic acid [4-(tert-butyl-dimethyl-silanyloxy)-phenyl]-methyl-amide 
• 872168-52-0 imidazole-1-carboxylic acid [4-(tert-butyl-dimethyl-silanyloxy)-phenyl]-methyl-amide 
• 579-58-8 N-methyl-(4-acetamido)phenol 
• 13278-69-8 2-(4-hydroxy-N-methyl-anilino)-ethanol 
• 92873-40-0 4-[(7-chloro-quinolin-4-yl)-methyl-amino]-phenol 

Relevant articles and documents

A one-pot synthesis of metol sulphate employing phase-transfer catalysis

A one-pot two-step synthesis of metol sulphate using phase transfer catalysis is reported.