612-82-8

Basic information

• Product Name: 3,3'-Dimethylbenzidine dihydrochloride
• Synonyms: o-Tolidine2HCl;o-Tolidinedihydrochloride,ACS;4-Piperazin-1-yl-benzenesulfonamide;8-Piperazin-1-yl-quinoline;o-TOLIDINE DIHYDROCHLORIDE REAGENT (ACS);1,1-Biphenyl-4,4-diamine, 3,3-dimethyl-, dihydrochloride;DIMETHYLBENZIDINEDIHYDROCHLORIDE;3,3'-Dimethylbenzidine dihydrochloride
• CAS NO: 612-82-8
• Molecular Formula: C₁₄H₁₈N₂*2Cl
• Molecular Weight: 285.21
• EINECS: 210-322-5
• Product Categories: Intermediates of Dyes and Pigments;Biphenyl & Diphenyl ether
• Mol File: 612-82-8.mol
• Article Data: 0

Chemical Properties

• Melting Point: >300°C
• Boiling Point: 361 °C at 760 mmHg
• Flash Point: 205.1 °C
• Appearance: white to light yellow/Solid
• Vapor Pressure: 2.14E-05mmHg at 25°C
• Water Solubility: Soluble in water.
• Sensitive: Air Sensitive
• CAS DataBase Reference: 3,3'-Dimethylbenzidine dihydrochloride(CAS DataBase Reference)
• NIST Chemistry Reference: 3,3'-Dimethylbenzidine dihydrochloride(612-82-8)
• EPA Substance Registry System: 3,3'-Dimethylbenzidine dihydrochloride(612-82-8)

Safety Data

• Hazard Codes: T,N
• Statements: 45-22-51/53-68
• Safety Statements: 53-45-61
• RIDADR: UN 3077 9/PG 3
• WGK Germany: 3
• RTECS: DD1226000
• F: 3-8-9
• TSCA: Yes
• HazardClass: 6.1(b)
• PackingGroup: III
• Hazardous Substances Data: 612-82-8(Hazardous Substances Data)

Usage

Chemical Properties

light beige to grey-beige crystalline powder

Uses

Different sources of media describe the Uses of 612-82-8 differently. You can refer to the following data:
1. It is an indicator.
2. o-Tolidine dihydrochloride is used as a sensitive colorimetric reagent for gold and for free chlorine in water.

General Description

Light tan powder.

Air & Water Reactions

Soluble in water.

Reactivity Profile

Acidic organic/inorganic salts, such as 3,3'-Dimethylbenzidine dihydrochloride, are generally soluble in water. The resulting solutions contain moderate to high concentrations of hydrogen ions and have pH's of less than 7.0. They react as acids to neutralize bases. These neutralizations generate heat, but less or far less than is generated by neutralization of inorganic acids, inorganic oxoacids, and carboxylic acid. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible. Many of these compounds catalyze organic reactions.

Fire Hazard

Flash point data for 3,3'-Dimethylbenzidine dihydrochloride are not available, but 3,3'-Dimethylbenzidine dihydrochloride is probably combustible.

Safety Profile

Suspected carcinogen with experimental carcinogenic data. Mutation data reported. When heated to decomposition it emits very toxic fumes of HCl and NOx

InChI:InChI=1/C14H16N2.2ClH/c1-9-7-11(3-5-13(9)15)12-4-6-14(16)10(2)8-12;;/h3-8H,15-16H2,1-2H3;2*1H

Synthetic route

3-pyridinecarboxaldehyde (500-22-1) + 3,3'-dimethylbenzidine diammonium chloride (612-82-8) → 3,3'-dimethyl-N4-(pyridin-3-ylmethylene)biphenyl-4,4'-diamine

Conditions	Yield
With formic acid In ethanol; dichloromethane at 20℃; Schiff-base condensation;	82%

pyridine-4-carbaldehyde (872-85-5) + 3,3'-dimethylbenzidine diammonium chloride (612-82-8) → 3,3'-dimethyl-N4-(pyridin-4-ylmethylene)biphenyl-4,4'-diamine

Conditions	Yield
With formic acid In ethanol; dichloromethane at 20℃; Schiff-base condensation;	80%

hydrogenchloride (7647-01-0) + 3,3'-dimethylbenzidine diammonium chloride (612-82-8) + cadmium(II) chloride (10108-64-2) → bis(3,3'-dimethylbenzidine diammonium) tetrachloride cadmate dichloride

Conditions	Yield
In methanol excess of CdCl2 with 2 drops of concd.HCl in CH3OH added to soln. of ligand in CH3OH, stirred for 0.5 h; filtered, crystd., XRD;	40%

phosgene (75-44-5) + 3,3'-dimethylbenzidine diammonium chloride (612-82-8) → 4,4'-diisocyanato-3,3'-dimethylbiphenyl (91-97-4)

Conditions	Yield
With chlorobenzene

CYANAMID (420-04-2) + 3,3'-dimethylbenzidine diammonium chloride (612-82-8) → N,N'''-(3,3'-dimethyl-biphenyl-4,4'-diyl)-di-guanidine

Conditions	Yield
With ethanol

3,3'-dimethylbenzidine diammonium chloride (612-82-8) → N,N'-(3,3'-dimethyl-biphenyl-4,4'-diyl)-bis-carbamic acid dimethyl ester (16083-49-1)

Conditions	Yield
Multi-step reaction with 2 steps 1: chlorobenzene View Scheme

Downstream Products

• 91-97-4 4,4'-diisocyanato-3,3'-dimethylbiphenyl