2-Bromocyclohexanone

China [CN]

I. Basic Information

Chinese Name: 2-Bromocyclohexanone

English Name: 2-Bromocyclohexanone

CAS Number: 822-87-7

Molecular Formula: C₆H₉BrO

Molecular Weight: 177.04 (Calculated: C 40.69%, H 5.12%, Br 45.15%, O 9.04%)

II. Chemical Structure and Characteristics

Structural Analysis: The molecule is based on a cyclohexanone nucleus (a six-membered ring containing a ketone group). A bromine atom (-Br) is attached to the carbon atom at position 2. The ketone group (C=O) is ortho to the bromine atom, forming an α-bromoketone structure. Core Characteristics:

The ortho-position relationship between the bromine atom and the keto group makes the molecule highly reactive, allowing the bromine atom to readily leave, and the electron-withdrawing effect of the keto group enhances the acidity of the α-H group.

The six-membered ring can exist in a chair conformation, and the spatial positioning of the bromine atom and the keto group influences the reaction selectivity.

Two stereoisomers exist (R- and S-configurations), which may exhibit different reactivities.

III. Physical and Chemical Properties (Reference Data)

Appearance: Typically a colorless to pale yellow liquid or a low-melting solid.

Boiling Point: Approximately 86-88°C (12 mmHg, reduced pressure). Decomposes readily at normal pressure.

Density: Approximately 1.47 g/cm³ (20°C), higher due to the presence of bromine atoms.

Refractive Index: Approximately 1.505-1.510 (20°C).

Solubility: Slightly soluble in water, freely soluble in organic solvents such as ethanol, ether, dichloromethane, and acetone. Stability: It is relatively stable at room temperature, but it is prone to decomposition or elimination reactions when exposed to strong light, high temperature or strong alkali, and needs to be stored away from light.