2,5-Dibromtoluol

Bezeichnung:2,5-Dibromtoluol

CAS-Nr615-59-8

Englisch Name:2,5-Dibromotoluene

CBNumberCB5115976

SummenformelC7H6Br2

Molgewicht249.93

MOL-Datei615-59-8.mol

Synonyma

2,5-Dibromtoluol

2,5-Dibromtoluol physikalisch-chemischer Eigenschaften

Schmelzpunkt	5-6 °C (lit.)
Siedepunkt	135-136 °C/35 mmHg (lit.)
Dichte	1.815 g/mL at 25 °C (lit.)
Brechungsindex	1.601-1.603
Flammpunkt	110°C
storage temp.	Sealed in dry,Room Temperature
Löslichkeit	Chloroform (Sparingly), Ethyl Acetate (Slightly)
Aggregatzustand	Liquid
Farbe	Clear colorless to yellow
Wichte	1.815
BRN	1859123
InChI	1S/C7H6Br2/c1-5-4-6(8)2-3-7(5)9/h2-4H,1H3
InChIKey	QKEZTJYRBHOKHH-UHFFFAOYSA-N
SMILES	Cc1cc(Br)ccc1Br
CAS Datenbank	615-59-8(CAS DataBase Reference)
NIST chemische Informationen	Benzene, 1,4-dibromo-2-methyl-(615-59-8)
EPA chemische Informationen	2,5-Dibromotoluene (615-59-8)

Sicherheit

Kennzeichnung gefährlicher	Xi
R-Sätze:	36/37/38
S-Sätze:	24/25-37/39-26
WGK Germany	3
TSCA	TSCA listed
HS Code	29039990
Speicherklasse	10 - Combustible liquids
Hazard Classifications	Eye Irrit. 2 Skin Irrit. 2 STOT SE 3

Gefahreninformationscode (GHS)

2,5-Dibromotoluene Chemische Eigenschaften,Einsatz,Produktion Methoden

R-Sätze Betriebsanweisung:
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-Sätze Betriebsanweisung:
S24/25:Berührung mit den Augen und der Haut vermeiden.
S37/39:Bei der Arbeit geeignete Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
Chemische Eigenschaften
clear colourless to yellowish liquid
Verwenden
2,5-Dibromotoluene has been used:
- as internal standard for quantification of cyanide and thiocyanate in human saliva by GC-MS
- in the preparation of 2,5-bis(4′-alkoxycarbonylphenyl)styrenes, monomers required for the synthesis of mesogen-jacketed liquid-crystal polymers
Synthese

583-75-5

615-59-8

The general procedure for the synthesis of 2,5-dibromotoluene from 2-methyl-4-bromoaniline is as follows: 400 mL of 23% aqueous hydrobromic acid was added to a 2000 mL three-necked beaker, and 46.5 g (0.25 mol) of pre-melted 2-methyl-4-bromoaniline was slowly added. A mechanical stirrer was turned on and the reaction mixture was stirred continuously for 20 minutes and subsequently cooled to -50°C. This temperature was maintained and a solution of 22.4 g (0.33 mol) of sodium nitrite dissolved in 130 mL of water was added slowly and dropwise through a constant pressure dropping funnel over a period of 1 hour. Upon completion of the reaction, the resulting diazonium salt solution was added in batches to 100 mL of 47% hydrobromic acid solution containing 35.9 g (0.25 mol) of copper bromide at 0°C. The reaction system was gradually warmed to 70 °C and stirred at this temperature for 30 min. At the end of the reaction, it was cooled to room temperature and extracted with methyl tert-butyl ether (3 x 200 mL). The organic phases were combined, dried with anhydrous potassium carbonate and concentrated under reduced pressure to remove the solvent. The crude product was first initially purified by passing through a short silica gel column (silica gel 60, 40-63 μm, column diameter 60 mm, height 140 mm; eluent: n-hexane). Finally, the colorless oily product with a boiling point of 100-102 °C/10 mmHg was collected by decompression distillation in a yield of 36.1 g (58% yield). Calculated elemental analysis (C7H6Br2): C, 33.64; H, 2.42. Measured values: C, 33.79; H, 2.50.1H NMR (CDCl3, 400 MHz) δ: 7.39 (m, 1H, Ar-H), 7.37 (m, 1H, Ar-H), 7.18 (m, 1H, Ar-H), 2.38 (s, 3H, -CH3).13C NMR (CDCl3, 400 MHz) δ: 7.39 (m, 1H, Ar-H), 7.37 (m, 1H, Ar-H), 7.18 (m, 1H, Ar-H), 2.38 (s, 3H, -CH3). -CH3).13C NMR (CDCl3, 100 MHz) δ: 139.9, 133.6, 133.5, 130.3, 123.5, 120.9, 22.7.
Einzelnachweise
[1] Patent: WO2007/70041, 2007, A1. Location in patent: Page/Page column 109-110
[2] Justus Liebigs Annalen der Chemie, 1873, vol. 168, p. 153
[3] Justus Liebigs Annalen der Chemie, 1878, vol. 192, p. 202
[4] Chemische Berichte, 1880, vol. 13, p. 963
[5] Chemische Berichte, 1881, vol. 14, p. 417

2,5-Dibromotoluene Upstream-Materialien And Downstream Produkte

2,5-Dibromtoluol Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

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