Bromotoluene

Not to be confused with Benzyl bromide.

Bromotoluenes are aryl bromides based on toluene in which at least one aromatic hydrogen atom is replaced with a bromine atom. They have the general formula C₇H_8–nBr_n, where n = 1–5 is the number of bromine atoms.

Monobromotoluene

Monobromotoluenes are bromotoluenes containing one bromine atom. There are three isomers, each with the formula C₇H₇Br.

Properties

The isomers differ in the location of the bromine, but have the same chemical formula.

Monobromotoluene isomers[1][2][3]
Common name	o-bromotoluene	m-bromotoluene	p-bromotoluene
Structure
Systematic name	1-bromo-2-methylbenzene	1-bromo-3-methylbenzene	1-bromo-4-methylbenzene
Molecular formula	C7H7Br (C6H4BrCH3)
Molar mass	171.03 g/mol
Appearance	colorless liquid	colorless liquid	white crystalline solid
CAS number	[95-46-5]	[591-17-3]	[106-38-7]
Properties
Density and phase	1.431 g/ml, liquid	1.4099 g/ml, liquid	1.3995 g/ml, solid
Solubility in water	practically insoluble
Other solubilities	very soluble in ethanol, ether, benzene, carbon tetrachloride, acetone, chloroform
Melting point	-27.8 °C (-18.0 °F; -409.63 K)	-39.8 °C (-39.6 °F; -388.03 K)	28.5 °C (83.3 °F; 301.7 K)
Boiling point	181.7 °C (359.1 °F; 454.9 K)	183.7 °C (362.7 °F; 456.9 K)	184.5 °C (364.1 °F; 457.7 K)

Benzyl bromide is an isomer, which has a bromine substituted for one of the hydrogens of toluene's methyl group, and it is sometimes named α-bromotoluene.

Preparation

A laboratory route to p-bromotoluene proceeds from p-toluidine, which is diazotiized followed by treatment with copper(I) bromide.[4]

Uses

Bromotoluenes are precursors to many organic building blocks. For example, the methyl group may be oxidized using potassium permanganate to form the corresponding bromobenzoic acid.[5] The methyl group may also be partially oxidized to form bromobenzaldehyde.[6]

See also

• Chlorotoluene
• Iodotoluene

References

1. "2-Bromotoluene". PubChem. National Center for Biotechnology Information. Retrieved January 19, 2023.
2. "3-Bromotoluene". PubChem. National Center for Biotechnology Information. Retrieved January 19, 2023.
3. "4-Bromotoluene". PubChem. National Center for Biotechnology Information. Retrieved January 19, 2023.
4. Bigelow, L. A. (1925). "p-BROMOTOLUENE". Organic Syntheses. 5: 21. doi:10.15227/orgsyn.005.0021.
5. Bigelow, L. A. (1922). "A Study of Side-Chain Oxidations with Potassium Permanganate. Ii". Journal of the American Chemical Society. 44 (9): 2010–2019. doi:10.1021/ja01430a020.
6. Coleman, G. H.; Honeywell, G. E. (1937). "p-BROMOBENZALDEHYDE". Organic Syntheses. 17: 20. doi:10.15227/orgsyn.017.0020.