Durol

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Structural formula
Structural formula of Durol
General
Surname Durol
other names

1,2,4,5-tetramethylbenzene

Molecular formula C 10 H 14
Brief description

crystalline white solid

External identifiers / databases
CAS number 95-93-2
EC number 202-465-7
ECHA InfoCard 100.002.242
PubChem 7269
Wikidata Q907919
properties
Molar mass 134.22 g mol −1
Physical state

firmly

density

0.838 g cm −3 (25 ° C)

Melting point

79.2 ° C

boiling point

196.8 ° C

solubility

practically insoluble in water

Refractive index

1.4790 (81 ° C)

safety instructions
GHS labeling of hazardous substances
02 - Highly / extremely flammable

danger

H and P phrases H: 228-413
P: 210
Toxicological data

6990 mg kg −1 ( LD 50 ,  rat ,  oral )

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

Durol ( 1,2,4,5-tetramethylbenzene ) is a benzene substituted with four methyl groups and thus an aromatic hydrocarbon . With its isomers prehnitol  (1,2,3,4-tetramethylbenzene) and isodurol  (1,2,3,5-tetramethylbenzene) it belongs to the group of tetramethylbenzenes and also to the group of C 4 -benzenes .

History and characteristics

Durol was discovered by Paul Jannasch and Rudolph Fittig in 1870 . The discoverers report that it is the first hydrocarbon in the benzene series that is solid at room temperature. The name was therefore chosen after the Latin durus (= hard). It is a white crystalline solid and, due to its symmetry ( C 2 ), has the highest melting point of 79.2 ° C compared to the other two isomers.

Structural formula of Durol, lying, to clarify the symmetry

Two signals can be seen in a 1 H-NMR spectrum : the two aromatic hydrogen atoms (2H) and four methyl groups (12H); Durol is used as an internal standard .

presentation

It is represented by reacting methyl chloride in the presence of aluminum chloride with benzene or p- xylene , or by reacting formaldehyde / HCl with xylene mixtures. It is also a by-product of the methanol-to-gasoline process .

use

The substance is used, among other things, for the production of pyromellitic dianhydride .

literature

Individual evidence

  1. ↑ a b c d e f g h i j Entry on 1,2,4,5-tetramethylbenzene in the GESTIS substance database of the IFA , accessed on March 26, 2017(JavaScript required) .
  2. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-478.
  3. ↑ Paul Jannasch, Rudolph Fittig: "Ueber das Tetramethylbenzol", in: Zeitschrift für Chemie , 1870 , 6 , pp. 161-162 ( full text ).
  4. ↑ Christian Wiegand: “Origin and interpretation of important organic trivial names. I. Hydrocarbons of the Benzene Series ”, in: Angewandte Chemie , 1948 , 60  (4), pp. 109–111 ( doi: 10.1002 / anie.19480600407 ).
  5. ↑ Petr K. Sazonov, Vasyli A. Ivushkin, Galina A. Artamkina, Irina P. Beletskaya: "Metal carbonyl anions as model metal-centered nucleophiles in aromatic and vinylic substitution reactions", in: Arkivoc , 2003 , 10 , p. 323 -334 ( PDF ).
  6. ↑ E. Ador, A. Rilliet: “About hydrocarbons obtained by the action of chloromethyl on benzene in the presence of aluminum chloride”, in: Reports of the German Chemical Society , 1879 , 12  (1), pp. 329-332 ( doi: 10.1002 / cber.18790120191 ).
  7. ↑ Lee Irvin Smith: Durene In: Organic Syntheses . 10, 1930, p. 32, doi : 10.15227 / orgsyn.010.0032 ; Coll. Vol. 2, 1943, p. 248 ( PDF ).
  8. ↑ Julius v. Braun , Johannes Nelles: “Convenient synthesis of durol and pentamethylbenzene from crude xylene”, in: Reports of the German Chemical Society , 1934 , 67  (6), pp. 1094-1099 ( doi: 10.1002 / cber.19340670635 ).
  9. ↑ John Packer, P. Kooy, CM Kirk, Claire Wrinkles: "The Production of Methanol and Gasoline"; New Zealand Institute of Chemistry ( PDF ).

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