2,4-DICHLOROTOLUENE

PRODUCT IDENTIFICATION

CAS NO 95-73-8

2,4-DICHLOROTOLUENE

EINECS NO. 202-445-8
FORMULA C7H6Cl2
MOL WT. 161.03
H.S. CODE  

TOXICITY

Oral rat LD50: 2400 mg/kg
SYNONYMS 2,4-二氯甲苯; 1,5-Dichloro-2-methylbenzene;
2,4-Dichloromethylbenzene; 2,4-Dichloro-1-methylbenzene; 2,4-DCT;

SMILES

 

CLASSIFICATION

ORGANOCHLORIDES /

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE clear liquid
MELTING POINT -13.5 C
BOILING POINT 200 C
SPECIFIC GRAVITY 1.25
SOLUBILITY IN WATER

Insoluble

pH

 

VAPOR DENSITY 5.6
AUTOIGNITION

 

NFPA RATINGS Health: 3; Flammability: 2; Reactivity: 0

REFRACTIVE INDEX

 
FLASH POINT

79 C

STABILITY Stable under ordinary conditions

APPLICATIONS

When substituted benzene molecules undergo electrophilic substitution reactions, substituents on a benzene ring can influence the reactivity. Activating substituents that activate the benzene ring toward electrophilic attack can alter the reaction rate or products by electronically or sterically affecting the interaction of the two reactants. deactivating substituents removes electron density from the benzene ring, making electrophilic aromatic substitution reactions slower and more difficult than benzene itself. For example, a hydroxy or methoxy substituent in phenol and anisole increases the rate of electrophilic substitution, while a nitro substituent decreases the ring's reactivity. Electron donating substituents activate the benzene ring toward electrophilic attack, and electron withdrawing substituents deactivate the ring, making it less reactive to electrophilic attack. The strongest activating substituents are the amino (-NH2) and hydroxyl (-OH) groups.

Reactivity Effects

Activating substituents

Deactivating substituents

Strong

-NH2, -NHR, -NR2, -OH, -O-

-NO2, -NR3+, -CF3, CCl3

Moderate

-NHCOCH3, -NHCOR, -OCH3,-OR

-CN, -SO3H, -COOH, -COOR, -COH, -COR

Weak

-CH3, -C2H5, -R, -C6H5

-F, -Cl, -Br, -I

Toluene, aniline and phenol are activated aromatic compounds. Examples of deactivated aromatic compounds are nitrobenzene, benzaldehyde and halogenated benzenes.

Activating substituents generally direct substitution to the ortho and para positions where substitutions must take place. With some exceptions, deactivating substituents direct to the meta position. Deactivating substituents which orient ortho and para- positions are the halogens (-F, -Cl, -Br, -I) and -CH2Cl, and -CH=CHNO2

When disubstituted benzene molecules undergo electrophilic substitution reactions, a new substituent is directed depends on the orientation of the existing substituents and their individual effects; whether the groups have cooperative or antagonistic directing effects. Ortho position is the most reactive towards electrophile due to the highest electron density ortho positions. But this increased reactivity is countervailed by steric hindrance between substituent and electrophile.

A nucleophilic substitution is a substitution reaction which the nucleophile displaces a good leaving group, such as a halide on an aromatic ring. This mechanism is called SNAr ( the two-step addition-elimination mechanism), where electron withdrawing substituents activate the ring towards nucleophilic attack. Addition-elimination reactions usually occur at sp2 or sp hybridized carbon atoms, in contrast to SN1 and SN2 at sp3. Chloro and bromobenzene reacts with the very strong base sodium amide (NaNH2) to give good yields of aniline. Other nucleophilic aromatic substitution mechanisms include benzyne mechanism and free radical (SRN1) mechanism.

Common reactions of substituent groups on benzene ring include:
  • Conversion of halogens into other various substituents
  • Modifying activating substituents
  • Oxidative degradation of alkyl chain
  • Reduction of nitro or carbonyl substituents
  • Reversibility of the aromatic sulfonation reaction

Dichlorotoluenes are clear volatile liquids; insoluble in water. These materials are in neutral, acidic or alkaline solution. They are used as high boiling point solvents and as intermediates for the synthesis of various organic chemicals of chlorinated-nitrated pesticides and medicinal products. Position isomers are:

Product

CAS RN

EINECS RN

BOILING POINT

2,3-Dichlorotoluene 32768-54-0 251-203-8

207.5 C

2,4-Dichlorotoluene 95-73-8 202-445-8

201 C

2,5-Dichlorotoluene 19398-61-9 243-032-2

200 C

2,6-Dichlorotoluene 118-69-4 204-269-7

198 C

3,4-Dichlorotoluene 95-75-0 202-447-9

208.5 C

3,5-Dichlorotoluene 25186-47-4 246-722-1

201.5 C

SALES SPECIFICATION

APPEARANCE

clear liquid

ASSAY

99.0% min

ISOMER IMPURITY

1.0% max

TRANSPORTATION
PACKING 250kgs in drum
HAZARD CLASS  
UN NO.  
OTHER INFORMATION
Hazard Symbols: XI, Risk Phrases: 22/36/37/38, Safety Phrases: 24/25/28A/37/45