4-Bromomethyl-1,2-dihydroquinoline-2-one
[CAS# 4876-10-2]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Quinoline compound
• Name: 4-Bromomethyl-1,2-dihydroquinoline-2-one
• Molecular Formula: C₁₀H₈BrNO
• Molecular Weight: 238.08
• CAS Registry Number: 4876-10-2
• EC Number: 679-473-6
• SMILES: C1=CC=C2C(=C1)C(=CC(=O)N2)CBr

Properties

• Density: 1.5±0.1 g/cm³ Calc.^*
• Melting point: 254 °C (Decomposes) (Expl.)
• Boiling point: 391.8±42.0 °C 760 mmHg (Calc.)^*
• Flash point: 190.8±27.9 °C (Calc.)^*
• Index of refraction: 1.616 (Calc.)^*

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

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H314-H315-H318-H319
• Safety Statements: P260-P264-P264+P265-P280-P301+P330+P331-P302+P352-P302+P361+P354-P304+P340-P305+P351+P338-P305+P354+P338-P316-P317-P321-P332+P317-P337+P317-P362+P364-P363-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin corrosion	Skin Corr.	1B	H314
Skin irritation	Skin Irrit.	2	H315
Serious eye damage	Eye Dam.	1	H318

Discovery and Applications

4-Bromomethyl-1,2-dihydroquinoline-2-one is a synthetic heterocyclic compound belonging to the quinolinone family, which has attracted attention due to its structural framework that serves as a versatile building block in medicinal chemistry. Quinolin-2-one derivatives have long been studied for their biological activity, including antimicrobial, anticancer, and anti-inflammatory properties, and the incorporation of a bromomethyl group at the 4-position introduces a highly reactive functional handle suitable for further chemical transformations.

The discovery of quinolin-2-one derivatives dates back to investigations into natural alkaloids containing quinoline frameworks in the late 19th and early 20th centuries. Subsequent synthetic approaches enabled the preparation of a wide range of analogues with substitutions on the heterocyclic ring system. Among them, 4-bromomethyl-1,2-dihydroquinoline-2-one was identified as a useful intermediate that could undergo nucleophilic substitution reactions, enabling the introduction of various substituents such as amines, thiols, or oxygen-based nucleophiles. This reactivity stems from the benzylic bromomethyl group, which is prone to substitution, making the compound highly adaptable for synthetic applications.

In pharmaceutical research, compounds based on the 1,2-dihydroquinolin-2-one core have been evaluated as scaffolds for drug discovery. The introduction of substituents at the 4-position often influences biological activity, and the bromomethyl derivative serves as a key starting material for creating libraries of analogues. Researchers have used such intermediates in the design of potential enzyme inhibitors, receptor ligands, and bioactive molecules targeting neurological and oncological pathways. While the bromomethyl compound itself is not typically the final active pharmaceutical ingredient, its role in enabling the rapid synthesis of derivative molecules is central to modern medicinal chemistry workflows.

Beyond pharmaceutical applications, 4-bromomethyl-1,2-dihydroquinoline-2-one also has significance in materials science and chemical biology. Quinolinone derivatives with functional substituents can exhibit fluorescence and other useful photophysical properties, making them candidates for probes in biological imaging or components in organic electronic materials. The bromomethyl functionality again allows for modular derivatization, enabling chemists to link the quinolinone scaffold to other molecular frameworks or functional groups.

Synthetic methods for producing 4-bromomethyl-1,2-dihydroquinoline-2-one typically involve the cyclization of suitably substituted precursors, followed by bromination at the benzylic position. Halogenation strategies using N-bromosuccinimide (NBS) under controlled conditions are commonly applied to introduce the bromomethyl group selectively without over-bromination of the aromatic system. This controlled synthesis has made the compound a reliable intermediate available for research use.

Overall, 4-bromomethyl-1,2-dihydroquinoline-2-one is best understood as a synthetic intermediate of considerable importance, valued for its reactivity and adaptability in producing a wide variety of derivatives. Its applications span drug discovery, organic synthesis, and materials chemistry, demonstrating how strategically placed functional groups on heterocyclic scaffolds can greatly expand the chemical utility of a compound. By serving as a key intermediate, it continues to support the development of novel molecules in both academic and industrial research.

References

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DOI: 10.1007/s40010-016-0337-2

2015. Scaffold-based design of xanthine as highly potent inhibitors of DPP-IV for improving glucose homeostasis in DIO mice. Molecular Diversity.
DOI: 10.1007/s11030-015-9570-x

2012. Synthesis and molecular structure of novel 2-(alkylthio)-4-chloro-N-(4,5-dihydro-5-oxo-1H-1,2,4-triazol-3-yl)-5-methylbenzenesulfonamides with potential anticancer activity. Monatshefte für Chemie - Chemical Monthly.
DOI: 10.1007/s00706-012-0849-7