m -toluidine

Structural formula
General
Surname	m -toluidine
other names	3-methylaniline; meta- toluidine; m -aminotoluene; meta- aminotoluene; 3-aminotoluene; m -methylaniline; meta- methylaniline; 3-methylaniline; 1-amino-3-methylbenzene;
Molecular formula	C 7 H 9 N
Brief description	colorless to red-brown oily liquid
External identifiers / databases
EC number	203-583-1
ECHA InfoCard	100.003.258
PubChem	7934
ChemSpider	13860692
Wikidata	Q1880736
properties
Molar mass	107.16 g mol −1
Physical state	liquid
density	0.99 g cm −3
Melting point	−31 ° C
boiling point	203 ° C
Vapor pressure	0.3 mbar (20 ° C)
pK s value	4.70 (the conjugate acid BH + )
solubility	little in water (10 g l −1 at 20 ° C)
Refractive index	1.5670
safety instructions
H and P phrases	H: 301 + 311 + 331-319-373-410
	P: 261-273-280-301 + 310-305 + 351 + 338-311
MAK	Switzerland: 2 ml m −3 or 9 mg m −3
Toxicological data	450 mg kg −1 ( LD 50 , rat , oral ) ; 3250 mg kg −1 ( LD 50 , rabbit , transdermal ) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

m -Toluidine ( meta -Toluidine) is a chemical compound from the group of aromatic, simply methylated anilines and is isomeric to o -Toluidine and p- Toluidine .

Extraction and presentation

All three isomeric toluidines are produced from nitrotoluenes ( accessible from toluene by nitration ) by reduction. The reduction can be carried out on the one hand with iron, acetic acid and hydrochloric acid ( Béchamp reduction ). Today, catalytic hydrogenation with Raney nickel predominates . Lower, aliphatic alcohols ( methanol , ethanol , n- propanol or iso- propanol ) are often used here as solvents . The hydrogenation generally takes place at pressures between 3 bar and 20 bar H ₂ pressure (so-called low-pressure hydrogenation) or at 20 to 50 bar (so-called medium-pressure hydrogenation ).

properties

m -Toluidine is an oily, colorless to yellowish liquid, which turns reddish-brown when exposed to light and air, is not very volatile, is difficult to ignite and is sparingly soluble in water. It has a conductivity of 5.5 × 10 ⁻⁸ S / m at 25 ° C.

All Toluidine are weak bases , their pK _s are values in the same order as aniline (4,603).

According to Antoine, the vapor pressure functions result according to log ₁₀ ( p ) = A− (B / ( T + C)) ( p in bar, T in K) as follows:

Vapor pressure functions of the toluidines
Type	T in K	A.	B.	C.
o -Toluidine	391.6-473.4	4.19168	1617.232	-87.126
m -toluidine	394.9-476.5	4.19983	1618.386	−90.631
p -toluidine	315-473.5	4.71884	1961,716	−57.0

use

The toluidines used to be of great importance almost exclusively as intermediate products for the production of dyes and pigments . Some herbicides are now also produced on the basis of these compounds.

The cresols can be obtained from the toluidines via diazotization (and subsequent “ boiling ”) .

m -Toluidine is contained in jet fuel, developers in color photography, electrophotographic materials and is used in the production of dyes , vulcanization accelerators, textile auxiliaries, pharmaceuticals and polyester resins.

An important azo dyes based on 3-methylaniline is Direct Yellow 50 ( CI 29025).

Chemical structure	Surname	use
	6-chloro-3-methylaniline	for azo dyes
	3-aminotoluene-4-sulfonic acid	as an intermediate for azo dyes and triphenylmethane dyes
	3-aminotoluene-6-sulfonic acid	as an intermediate for azo dyes
	3-amino-6-chlorotoluene-4-sulfonic acid	as a diazo component for azo dyes

safety instructions

The vapors of m- toluidine can form an explosive mixture with air ( flash point 85 ° C, ignition temperature 480 ° C). It attacks various plastics.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Entry on m-toluidine in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
↑ ^a ^b CRC Handbook of Tables for Organic Compound Identification , Third Edition, 1984, ISBN 0-8493-0303-6 .
↑ JS Bowers, Jr .: Toluidines in Ullmann's Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, doi : 10.1002 / 14356007.a27_159 .
↑ Entry on m-toluidine in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 108-44-1 or M-toluidine ), accessed on November 2, 2015.
↑ ^a ^b R. R. Dreisbach, SA Shrader: Vapor Pressure Temperature Data on Some Organic Compounds . In: Ind. Eng. Chem. Band 41 , no. 12 , 1949, pp. 2879-2880 , doi : 10.1021 / ie50480a054 .
^ Daniel R. Stull: Vapor Pressure of Pure Substances. Organic and Inorganic Compounds . In: Ind. Eng. Chem. Band 39 , no. 4 , 1947, pp. 517-540 , doi : 10.1021 / ie50448a022 .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Entry on m-toluidine in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .

[CRC-2] CRC Handbook of Tables for Organic Compound Identification , Third Edition, 1984, ISBN 0-8493-0303-6 .

[Ullmann-3] JS Bowers, Jr .: Toluidines in Ullmann's Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, doi : 10.1002 / 14356007.a27_159 .

[CLP_100.003.258-4] Entry on m-toluidine in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[5] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 108-44-1 or M-toluidine ), accessed on November 2, 2015.

[Dreisbach-6] R. R. Dreisbach, SA Shrader: Vapor Pressure Temperature Data on Some Organic Compounds . In: Ind. Eng. Chem. Band 41 , no. 12 , 1949, pp. 2879-2880 , doi : 10.1021 / ie50480a054 .

[Stull-7] Daniel R. Stull: Vapor Pressure of Pure Substances. Organic and Inorganic Compounds . In: Ind. Eng. Chem. Band 39 , no. 4 , 1947, pp. 517-540 , doi : 10.1021 / ie50448a022 .