6-Bromo-3,4-dihydronaphthalen-1(2H)-one

This compound is typically obtained as a crystalline solid ranging from off-white to pale yellow. Its molecular formula is C10H9BrO, corresponding to a molecular weight of 225.08. The melting point generally falls within the range of 78–82 °C, reflecting a well-defined crystal lattice. The calculated density is approximately 1.56 g/cm³ under ambient conditions. It exhibits good solubility in common organic solvents including dichloromethane, ethyl acetate, tetrahydrofuran, and methanol, while showing limited solubility in water and negligible solubility in non-polar solvents such as hexane. The molecule contains a 3,4-dihydronaphthalen-1(2H)-one core with a bromine atom at the 6-position. This structure features a partially saturated bicyclic system combining an aromatic ring with a cyclohexenone moiety. The ketone carbonyl is susceptible to nucleophilic addition and condensation reactions, while the bromine atom is activated toward cross-coupling and nucleophilic substitution. Storage in tightly sealed containers protected from light and moisture at reduced temperature (2–8 °C) is recommended to prevent decomposition. Contact with strong nucleophiles, strong bases, and strong oxidizing agents should be avoided.

6-Bromo-3,4-dihydronaphthalen-1(2H)-one is a brominated α-tetralone derivative featuring a partially saturated bicyclic ring system. The molecule consists of a benzene ring fused to a cyclohexenone ring, with the double bond located between the 3 and 4 positions and the carbonyl at the 1-position. This creates an α,β-unsaturated ketone system where the double bond is conjugated with both the aromatic ring and the carbonyl, influencing its reactivity and spectroscopic properties. The bromine atom at the 6-position on the aromatic ring provides a versatile handle for transition-metal-catalyzed cross-coupling reactions such as Suzuki, Sonogashira, and Buchwald-Hartwig couplings. The ketone functionality can undergo reduction, alkylation, or condensation reactions, enabling further elaboration of the scaffold. The partially saturated ring system imparts conformational rigidity while maintaining some flexibility, making this compound a valuable building block for constructing more complex molecules in medicinal chemistry and natural product synthesis.

Pharmaceutical Intermediate
This brominated α-tetralone derivative is employed in the synthesis of compounds with potential activity against cancer and neurological disorders. The ketone can be transformed via reductive amination to introduce basic amine side chains, while the bromine enables palladium-catalyzed cross-couplings to attach diverse aryl or heteroaryl groups. The rigid bicyclic core appears in various bioactive molecules, including selective estrogen receptor modulators and melatonin receptor ligands.

Building Block for Heterocyclic Synthesis
The α,β-unsaturated ketone system enables cyclocondensation reactions with various dinucleophiles to form fused heterocyclic systems such as naphthopyrazoles, naphthoisoxazoles, and naphthopyrimidines. These ring systems are investigated for their pharmacological properties, with the rigid naphthalene-like core providing conformational constraint beneficial for target recognition. The bromine allows for further diversification after heterocycle formation.

Natural Product Synthesis
This compound serves as a key intermediate in the total synthesis of several natural products containing the tetralone or naphthalene framework. The ketone can be elaborated to introduce stereocenters through asymmetric reduction or alkylation, while the bromine provides a handle for constructing more complex polycyclic architectures via cross-coupling and cyclization sequences.

Organic Synthesis Building Block
As a versatile synthetic intermediate, 6-bromo-3,4-dihydronaphthalen-1(2H)-one participates in diverse transformations including nucleophilic addition to the ketone, palladium-catalyzed cross-couplings at the bromine site, and conjugate additions to the enone system. The combination of an electrophilic carbonyl and a halogen handle enables sequential functionalization, allowing rapid construction of libraries of tetralone-based compounds for drug discovery and materials chemistry applications.