2-Bromo-6-fluorotoluene
[CAS 1422-54-4]

Identification

• Classification: Organic raw materials >> Organic fluorine compound >> Fluorotoluene series
• Name: 2-Bromo-6-fluorotoluene
• Synonyms: 1-bromo-3-fluoro-2-methylbenzene
• Molecular Formula: C₇H₆BrF
• Molecular Weight: 189.02
• CAS Registry Number: 1422-54-4
• EC Number: 642-646-1
• SMILES: CC1=C(C=CC=C1Br)F

Properties

• Density: 1.5±0.1 g/cm³ Calc.^*, 1.53 g/mL (Expl.)
• Boiling point: 180.2±20.0 °C 760 mmHg (Calc.)^*, 217.3 - 218.7 °C (Expl.)
• Flash point: 65.2±16.6 °C (Calc.)^*
• Index of refraction: 1.527 (Calc.)^*, 1.535 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 WarningGHS02
• Risk Statements: H227-H315-H319-H335
• Safety Statements: P210-P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P370+P378-P403-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2A	H319
Flammable liquids	Flam. Liq.	4	H227

chemBlink Chemical Story

A small aromatic molecule can be valuable not because it does one spectacular reaction, but because it carries two different kinds of chemical "handles." 2-Bromo-6-fluorotoluene is a good example. Its benzene ring contains a methyl group flanked by bromine and fluorine. The two halogens look similar on paper, yet synthetic chemists usually treat them very differently.

The carbon-bromine bond is the more obvious construction site. Aryl bromides are widely used in palladium-catalyzed cross-coupling chemistry, where the bromine can be replaced by carbon-, nitrogen-, oxygen-, or other groups. In a medicinal-chemistry sequence, that means the brominated position can be elaborated while the fluorine is often left untouched. Fluorine, in turn, is frequently retained because a single C-F bond can alter lipophilicity, metabolic stability, conformation, and binding interactions without adding much steric bulk. The value of 2-bromo-6-fluorotoluene therefore lies in this difference in reactivity: one substituent is a convenient exit point for synthesis, while the other can survive as part of the final molecular design.

The substitution pattern also matters. Bromine and fluorine occupy the two positions next to the methyl group, creating a crowded aromatic edge. That steric environment can influence metalation, coupling rates, and the conformations of products built from the ring. Such apparently modest positional differences are why medicinal-chemistry catalogs contain many closely related halogenated toluenes: the correct regioisomer can determine whether a later synthetic route reaches the desired three-dimensional arrangement.

This compound has appeared as a starting material in pharmaceutical patent chemistry, illustrating the role of halogenated aromatics as route-defining building blocks rather than active drugs themselves. It can also be oxidized at the benzylic methyl group to reach more functionalized derivatives such as fluorobromobenzyl or benzaldehyde intermediates, while the aryl bromide remains available for further diversification.

The broader lesson is that synthetic usefulness often comes from orthogonality. Bromine and fluorine are both halogens, but in a molecule such as 2-bromo-6-fluorotoluene they perform different jobs. The bromine invites transformation; the fluorine often provides a property that chemists deliberately preserve. A simple bottle of halogenated toluene can therefore serve as a branching point from which many more elaborate molecules are built.

References:
1. PubChem, 1-Bromo-3-fluoro-2-methylbenzene, CID 2736335.
2. TCI, 2-Bromo-6-fluorotoluene, CAS 1422-54-4.
3. WO2007031828A2, Therapeutic pyrrolidines.

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