2-Bromo-1-phenyl-pentan-1-one, identified by the CAS registry number 49851-31-2, is an organic compound that appears in chemical databases and academic literature primarily as a reference substance in organic chemistry. Known by its systematic name and frequently indexed through its CAS number, this compound exemplifies a class of aromatic ketones bearing an α-bromo substituent. The combination of an aromatic ring, a carbonyl group, and a halogenated side chain makes it structurally interesting for theoretical discussions, analytical characterization, and general chemical education.
This article provides an overview of its nomenclature, molecular features, and broader scientific considerations, without focusing on experimental procedures.
Nomenclature and Identification (CAS 49851-31-2)
The name 2-Bromo-1-phenyl-pentan-1-one follows standard IUPAC conventions. The parent structure, “1-phenyl-pentan-1-one,” describes a five-carbon aliphatic chain with a phenyl group and a ketone functional group located at the first carbon. The prefix “2-bromo” indicates the presence of a bromine atom attached to the second carbon atom of the pentyl chain. This systematic naming ensures that chemists can infer the basic molecular architecture directly from the name.
The CAS number 49851-31-2 serves as a unique numerical identifier assigned by the Chemical Abstracts Service. Unlike chemical names, which may vary slightly depending on nomenclature style or language, the CAS number is unambiguous. Researchers, librarians, and regulatory bodies rely on CAS numbers to retrieve accurate information on substances, including physical data, safety documentation, and bibliographic references. For 2-bromo-1-phenyl-pentan-1-one, the CAS listing consolidates data from multiple sources and helps distinguish it from structurally similar brominated ketones.
Molecular Structure and Physicochemical Characteristics
From a structural perspective, 2-bromo-1-phenyl-pentan-1-one belongs to the broader family of α-halo aromatic ketones. The molecule contains three key components: an aromatic phenyl ring, a carbonyl (C=O) group, and an aliphatic chain substituted with bromine. The phenyl ring contributes a conjugated π-electron system, which influences the compound’s electronic properties and spectroscopic behavior. The carbonyl group introduces polarity and serves as a defining functional group of ketones.
The bromine atom at the α-position relative to the carbonyl group is particularly significant from a theoretical standpoint. Halogen substitution at this position alters electron distribution within the molecule and affects how the compound is discussed in terms of reactivity trends and structure–property relationships. In spectroscopic analysis, these features are reflected in characteristic signals:
Infrared spectroscopy (IR) typically shows a strong absorption band associated with the carbonyl stretching vibration.
Nuclear magnetic resonance (NMR) spectra display aromatic proton signals from the phenyl ring and distinct resonances for the aliphatic chain influenced by the bromine substituent.
Mass spectrometry (MS) often reveals isotopic patterns associated with bromine, which naturally occurs as two major isotopes.
While precise physical constants such as melting point or boiling point may vary depending on purity and measurement conditions, compounds of this type are generally soluble in common organic solvents and are handled within controlled laboratory environments for analytical or reference purposes.
Scientific Context, Safety, and Regulatory Considerations
In modern scientific discourse, 2-bromo-1-phenyl-pentan-1-one (CAS 49851-31-2) is primarily discussed in the context of chemical structure analysis, data compilation, and theoretical modeling rather than as a commodity chemical. Its presence in databases reflects the broader goal of documenting chemical diversity and enabling comparative studies across related compounds. Such documentation supports cheminformatics, quantitative structure–activity relationship (QSAR) research, and educational use in organic chemistry.
As with many halogenated organic compounds, considerations of safety and compliance are essential. Although detailed hazard classifications depend on authoritative safety data sheets, substances containing bromine and reactive functional groups are typically managed with standard laboratory precautions. These include appropriate personal protective equipment, controlled storage, and adherence to institutional and regulatory guidelines. The CAS registration system plays a role here as well, linking the compound to regulatory frameworks that govern transport, labeling, and usage.
From a regulatory and ethical perspective, discussions surrounding compounds like 2-bromo-1-phenyl-pentan-1-one emphasize responsible scientific use. Academic and industrial researchers rely on transparent reporting, regulatory compliance, and risk awareness to ensure that chemical knowledge is applied constructively. Consequently, most references to this compound remain descriptive, focusing on its identity, structure, and role within chemical classification schemes.
2-Bromo-1-phenyl-pentan-1-one, cataloged under CAS 49851-31-2, represents a well-defined organic molecule whose significance lies in its structural features and its place within chemical information systems. Through its systematic name, CAS identification, and characteristic molecular components, it serves as a useful example for understanding aromatic ketones and α-halo substitutions. Rather than being notable for large-scale applications, its value is found in scientific documentation, analytical characterization, and theoretical discussion.
By examining compounds like this within a framework of safety, regulation, and academic inquiry, the chemical sciences continue to build a comprehensive and responsible body of knowledge.
