2-Bromo-3-fluoro-6-methylpyridine
[CAS 374633-36-0]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridine compound >> Methylpyridine
• Name: 2-Bromo-3-fluoro-6-methylpyridine
• Synonyms: 6-Bromo-5-fluoro-2-picoline
• Molecular Formula: C₆H₅BrFN
• Molecular Weight: 190.01
• CAS Registry Number: 374633-36-0
• EC Number: 696-217-9
• SMILES: CC1=NC(=C(C=C1)F)Br

Properties

• Density: 1.6±0.1 g/cm³ Calc.^*
• Boiling point: 185.6±35.0 °C 760 mmHg (Calc.)^*
• Flash point: 66.0±25.9 °C (Calc.)^*
• Index of refraction: 1.53 (Calc.)^*

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H312-H315-H319-H332-H335
• Safety Statements: P261-P264-P264+P265-P270-P271-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P317-P319-P321-P330-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H332
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H312

chemBlink Chemical Story

2-Bromo-3-fluoro-6-methylpyridine, CAS 374633-36-0, is a halogenated pyridine building block containing three deliberately differentiated features: a ring nitrogen, a bromine atom, and a fluorine atom together with a methyl substituent. Public literature for this exact CAS number is limited, so its most defensible description is as a synthetic intermediate rather than as a compound with a single established end use.

The bromine at the 2-position provides the most obvious synthetic handle. Heteroaryl bromides can participate in palladium-catalyzed Suzuki-Miyaura, Stille, Negishi, Buchwald-Hartwig and related cross-coupling reactions. This allows the bromine to be replaced by carbon or nitrogen substituents while retaining the pyridine framework.

Fluorine at the 3-position generally serves a different role. An aryl C-F bond is much less likely than C-Br to undergo ordinary palladium cross-coupling, so fluorine can often remain in the product while bromine is selectively transformed. It then contributes its strong electronic effect and small steric footprint to the final molecule. The methyl group at position 6 adds another source of steric and hydrophobic tuning adjacent to the ring nitrogen.

The pyridine nitrogen itself can act as a basic site, hydrogen-bond acceptor or metal-coordination site. These properties make substituted pyridines common fragments in medicinal, agrochemical and ligand chemistry. Having Br, F and CH3 at defined positions gives chemists several independent variables around the same heteroaromatic core.

The compound therefore illustrates "orthogonal functionality": different substituents are installed because they are meant to behave differently. Bromine is usually the replaceable synthetic handle; fluorine is often retained as an electronic design element; methyl modifies local shape; and pyridine nitrogen contributes heteroaromatic polarity. A small molecule can thus encode several future synthetic decisions before the first coupling reaction is performed.

References:
1. Commercial chemical databases, 2-Bromo-3-fluoro-6-methylpyridine, CAS 374633-36-0.
2. Miyaura N, Suzuki A. Chem Rev. 1995;95:2457-2483.
3. Joule JA, Mills K. Heterocyclic Chemistry. 5th ed. Wiley, 2010.

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