Dichlorotoluenes

Dichlorotoluenes (dichloromethylbenzenes) form a group of substances that are derived from both toluene and chlorobenzene . The structure consists of a benzene ring with an attached methyl group  (–CH ₃ ) and two chlorine atoms  (–Cl) as substituents . Their different arrangement results in six constitutional isomers with the empirical formula C ₇ H ₆ Cl ₂ . Dichlorotoluenes therefore belong to the polychlorinated toluenes.

properties

The dichlorotoluenes are practically insoluble in water; however, they are in other organic solvents, such as. B. benzene, alcohol, ether, ethyl acetate and chloroform, soluble.

Dichlorotoluenes
Surname	2,3-dichlorotoluene	2,4-dichlorotoluene	2,5 dichlorotoluene	2,6 dichlorotoluene	3,4-dichlorotoluene	3,5 dichlorotoluene
other names	1,2-dichloro- 3-methylbenzene	1,3-dichloro- 4-methylbenzene	1,4-dichloro- 3-methylbenzene	1,3-dichloro- 2-methylbenzene	1,2-dichloro- 4-methylbenzene	1,3-dichloro- 5-methylbenzene
Structural formula
CAS number	32768-54-0	95-73-8	19398-61-9	118-69-4	95-75-0	25186-47-4
	29797-40-8 (mixture of isomers)
ECHA InfoCard	100.046.534	100.002.224	100.039.105	100,003,882	100.002.226	100,042,460
	100.045.307 (mixture of isomers)
PubChem	34702	7254	29572	8368	7256	32834
Molecular formula	C 7 H 6 Cl 2
Molar mass	160.95 g mol −1
Physical state	liquid
Brief description	colorless liquid	colorless, flammable liquid with an aromatic odor	colorless liquid	colorless, flammable liquid with an aromatic odor	colorless liquid with a characteristic odor
Melting point	6 ° C	−13 ° C	4-5 ° C	2 ° C	−15 ° C
boiling point	207-208 ° C	201 ° C	197-200 ° C	196-203 ° C	200-202 ° C
density	1.23 g / cm 3	1.25 g / cm 3	1.25 g / cm 3	1.27 g / cm 3	1.25 g / cm 3
solubility	practically insoluble in water
GHS labeling	Caution	Caution	Caution	Caution	Caution	no classification available
H and P phrases	332	411	332	315-411	411	see above
	no EUH phrases	no EUH phrases	no EUH phrases	no EUH phrases	no EUH phrases	see above
	no P-phrases	273	no P-phrases	no P-phrases	262-273	see above
Tox data		2400 mg kg −1 ( LD 50 ,  rat ,  oral )

Extraction and presentation

The dichlorotoluenes can be obtained by chlorinating chlorotoluenes , which can be prepared from the toluidines by means of the Sandmeyer reaction .

use

Dichlorotoluenes are used, among other things, as a cleaning agent in the shipping industry, as a dye carrier in the textile industry and as a barrier liquid in vacuum pumps. 2,4-dichlorotoluene is a precursor for the production of 2,4-dichlorobenzoyl chloride and 2,4-dichlorobenzoic acid , which in turn is used for the production of dyes, pharmaceuticals and preservatives. 3,4-dichlorotoluene is used as an intermediate in the production of 3,4-dichlorobenzyl chloride (a precursor for disinfectants), 3,4-dichlorobenzaldehyde (a precursor for dyes) and 3,4-dichlorobenzoic acid .

See also

• Chlorotoluenes
• Chlorobenzyl chlorides
• Trichlorotoluenes , C ₇ H ₅ Cl ₃

• Tetrachlorotoluenes , C ₇ H ₄ Cl ₄

• Pentachlorotoluene , C ₇ H ₃ Cl ₅

safety instructions

Chlorotoluenes can decompose plastics and slightly corrode metals. The thermal decomposition of chlorotoluenes forms toxic and corrosive hydrogen chloride .

Individual evidence

1. ↑ Entry for CAS no. 29797-40-8 in the GESTIS substance database of the IFA , accessed on December 27, 2019(JavaScript required) .
2. ↑ ^{a b c d e f} data sheet 2,3-dichlorotoluene from Sigma-Aldrich , accessed on December 27, 2019 ( PDF ).
3. ↑ ^{a b c d e f g} Entry on 2,4-dichlorotoluene in the GESTIS substance database of the IFA , accessed on December 27, 2019(JavaScript required) .
4. ↑ ^{a b c d e f} data sheet 2,5-dichlorotoluene from Sigma-Aldrich , accessed on December 27, 2019 ( PDF ).
5. ↑ ^{a b c d e f} Entry on 2,6-dichlorotoluene in the GESTIS substance database of the IFA , accessed on December 27, 2019(JavaScript required) .
6. ↑ ^{a b c d e f} Entry on 3,4-dichlorotoluene in the GESTIS substance database of the IFA , accessed on December 27, 2019(JavaScript required) .
7. ^ Association of authors: Organikum , 19th edition, Johann Ambrosius Barth, Leipzig · Berlin · Heidelberg 1993, ISBN 3-335-00343-8 , p. 566.
8. ↑ Toxicological assessment of dichlorotoluene, technical mixture of isomers (PDF) at the professional association raw materials and chemical industry (BG RCI), accessed on August 22, 2012.
9. ↑ Toxicological assessment of 2,4-dichlorotoluene (PDF) at the professional association raw materials and chemical industry (BG RCI), accessed on August 22, 2012.
10. ↑ Toxicological assessment of 3,4-dichlorotoluene (PDF) at the professional association raw materials and chemical industry (BG RCI), accessed on August 22, 2012.