Chloranilines

In chemistry , the chloroanilines form a group of substances that are derived from both aniline and chlorobenzene . The structure consists of a benzene ring with an attached amino group  (–NH ₂ ) and chlorine  (–Cl) as substituents . Their different arrangements ( ortho , meta or para ) result in three constitutional isomers with the empirical formula C ₆ H ₆ ClN. In addition, there is also the isomeric N -chloroaniline .

Depending on the number of chlorine atoms (one, two, three, four or five) a distinction is also made between mono-, di- , tri- , tetra- and pentachloroanilines .

Representative

Chloranilines
Surname	2-chloroaniline	3-chloroaniline	4-chloroaniline
other names	o -chloraniline	m -chloraniline	p -chloraniline
Structural formula
CAS number	95-51-2	108-42-9	106-47-8
PubChem	7240	7932	7812
Molecular formula	C 6 H 6 ClN
Molar mass	127.57 g mol −1
Physical state	liquid		firmly
Brief description	colorless to yellowish liquid with an aromatic odor		colorless to yellowish crystalline solid with a slightly aromatic odor
Melting point	−3 ° C	−10 ° C	70 ° C
boiling point	209 ° C	230 ° C	232 ° C
density	1.21 g / cm 3	1.22 g / cm 3	1.43 g / cm 3
Vapor pressure (at 20 ° C)	0.13 mbar	0.03 mbar
pK s value (of the conjugate acid BH + )	2.65	3.52	4.00
solubility	hardly soluble in water (3–6 g / l)
GHS labeling	danger
H and P phrases	331-311-301-319-373-410	301 + 311 + 331-373-410	301-311-317-331-350-410
	no EUH phrases	no EUH phrases	no EUH phrases
	261-273-280-301 + 310-330-403 + 233	273-280-301 + 310 + 330-302 + 352 + 312-304 + 340 + 311-314	201-280-302 + 350-304 + 340-308 + 313-273
MAK			Switzerland: 0.04 ml m −3 or 0.2 mg m −3 (measured as inhalable dust )

properties

The 4-chloroaniline, which has the highest symmetry, has the highest melting point. All compounds in this group are classified as toxic and dangerous for the environment. Chloranilines are mostly used as intermediates in the synthesis of other chemical compounds such as pesticides, dyes and pharmaceuticals. Since the chloroanilines used in the synthesis are released during the natural breakdown of some of these substances (or even in the event of improper production), traces of the compounds can be found in groundwater and rivers. The substances can be detected using liquid chromatography.

use

Chloranilines are mostly used as intermediates in the synthesis of other chemical compounds such as pesticides , dyes and pharmaceuticals . After reductive cleavage of azo groups, 4-chloroaniline must not be released from textiles or leather products that come into direct contact with human skin for a long time (Appendix 1 of the Consumer Goods Ordinance ).

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry on o-chloroaniline in the GESTIS substance database of the IFA , accessed on March 4, 2020(JavaScript required) .
2. ↑ ^{a b c d e f g h i} Entry on m-chloroaniline in the GESTIS substance database of the IFA , accessed on March 4, 2020(JavaScript required) .
3. ↑ ^{a b c d e f g h} Entry on p-chloroaniline in the GESTIS substance database of the IFA , accessed on March 4, 2020(JavaScript required) .
4. ↑ CRC Handbook of Tables for Organic Compound Identification , Third Edition, 1984, ISBN 0-8493-0303-6 .
5. ↑ Swiss Accident Insurance Fund (Suva): Limit values ​​- Current MAK and BAT values (search for p-chloroaniline ), accessed on March 4, 2020.
6. ↑ Entry on mono-, di- and trichloroanilines in the GESTIS substance database of the IFA , accessed on May 10, 2008(JavaScript required) .
7. ↑ Organic pollutants in the area of ​​the Lower Mulde. ( Memento from October 25, 2005 in the Internet Archive )
8. ↑ Jacqueline Burkhardt, Joachim Hörder, Marian Pohl, Walburga Große Wichtrup, Sibylle Wilke: Data on the environment: the state of the environment in Germany . Ed .: Federal Environment Agency. Erich Schmidt Verlag, Berlin 2005, ISBN 3-503-09057-6 , p. 150 ( online [PDF]).
9. ↑ Method for the determination of p -chloroaniline.  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.