Molecular Structure of 3,3'-Dimethylbenzidine dihydrochloride (CAS NO.612-82-8):

IUPAC Name: 4-(4-amino-3-methylphenyl)-2-methylaniline dihydrochloride 
Empirical Formula: _C14H₁₈Cl₂N₂
Molecular Weight: 285.2121 
H bond acceptors: 2
H bond donors: 4
Freely Rotating Bonds: 3
Polar Surface Area: 0 Å²
EINECS: 210-322-5
Flash Point: 205.1 °C
Boiling Point: 361 °C
Melting Point: >300°C
Sensitive: Air Sensitive
Enthalpy of Vaporization: 60.67 kJ/mol
Vapour Pressure: 2.14E-05 mmHg at 25°C
Product Categories: Intermediates of Dyes and Pigments; Biphenyl & Diphenyl ether
Form: light beige to grey-beige crystalline powder
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
Smiles
c1(c2cc(c([NH2+])cc2)C)cc(c([NH2+])cc1)C.[ClH-].[ClH-]

Reported in NTP Carcinogenesis Studies (Drinking); Clear Evidence: rat NTPTR*    National Toxicology Program Technical Report Series. (Research Triangle Park, NC 27709) No. NTP-TR-390 ,1991. . Reported in EPA TSCA Inventory.

Suspected carcinogen with experimental carcinogenic data. Mutation data reported. When heated to decomposition it emits very toxic fumes of HCl and NO_x.
Safety information of 3,3'-Dimethylbenzidine dihydrochloride (CAS NO.612-82-8):
Hazard Codes: T,N
Risk Statements:
45: May cause cancer
22: Harmful if swallowed
51/53: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment
68: Possible risk of irreversible effects
Safety Statements:
53: Avoid exposure - obtain special instruction before use
45: In case of accident or if you feel unwell, seek medical advice immediately (show label where possible)
61: Avoid release to the environment. Refer to special instructions safety data sheet
RIDADR: UN 3077 9/PG 3
WGK Germany: 3
RTECS: DD1226000
F: 3-8-9
HazardClass: 6.1(b)
PackingGroup: III

 3,3'-Dimethylbenzidine dihydrochloride , with CAS number of 612-82-8, can be called [1,1'-Biphenyl]-4,4'-diamine, 3,3'-dimethyl-, dihydrochloride ; 3,3'-Dimethyl-4,4'-biphenyldiamine dihydrochloride ; 3,3'-Dimethylbenzidine dihydrochloride . It is a light beige to grey-beige crystalline powder, be 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.