Chemistry informtion about 2,4-Dimethylbenzyl Bromide (CAS NO.78831-87-5) is:
Synonyms: 2,4-Dimethylbenzyl Bromide ; Benzene, 1-(Bromomethyl)-2,4-Dimethyl- (7ci, 9ci) ; 2,4-Dimethylbenzyl Bromide,98%
MF: C₉H₁₁Br
MW: 199.09 
Density: 1.314 g/cm³
Flash Point: 101.7 °C
Boiling Point: 235.4 °C at 760 mmHg
Vapour Pressure: 0.0769 mmHg at 25°C
Enthalpy of Vaporization: 45.3 kJ/mol
Refractive Index: 1.568-1.57
Following is the molecular structure of  2,4-Dimethylbenzyl Bromide (CAS NO.78831-87-5) is:

Safty information about 2,4-Dimethylbenzyl Bromide (CAS NO.78831-87-5) :
Hazard Codes:
Xi: Irritant
Risk Statements:
R36/37/38:Irritating to eyes, respiratory system and skin.
Safety Statements:
S37/39:Wear suitable gloves and eye/face protection. 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
RIDADR: 3265

 2,4-Dimethylbenzyl Bromide (CAS NO.78831-87-5) is a clear colorless to light yellow liquid.
First Aid Measures:
Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.
Skin: Get medical aid. Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes.
Ingestion: Get medical aid. Wash mouth out with water.
Inhalation: Remove from exposure and move to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
Notes to Physician: Treat symptomatically and supportively. 
Handling and Storage:
Handling: Avoid breathing dust, vapor, mist, or gas. Avoid contact with skin and eyes.
Storage: Store in a cool, dry place. Store in a tightly closed container.