3-Acetylpyridine
[CAS# 350-03-8]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Lactone and oxygen-containing heterocyclic compound >> Thiazole, thiophene and pyridine
• Name: 3-Acetylpyridine
• Synonyms: 1-(3-pyridinyl)ethanone; Methyl 3-pyridyl ketone
• Molecular Formula: C₇H₇NO
• Molecular Weight: 121.14
• CAS Registry Number: 350-03-8
• EC Number: 206-496-7
• FEMA: 3424
• SMILES: CC(=O)C1=CN=CC=C1

Properties

• Density: 1.102 g/mL (Expl.)
• Melting point: 12-13 °C (Expl.)
• Boiling point: 220 °C (Expl.)
• Refractive index: 1.5346 (Expl.)
• Flash point: 104 °C (Expl.)
• Water solubility: Soluble in hot water

Safety Data

• Hazard Symbols: GHS06 Danger
• Risk Statements: H301
• Safety Statements: P264-P270-P301+P316-P321-P330-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	2	H300
Acute toxicity	Acute Tox.	3	H331
Acute toxicity	Acute Tox.	3	H311
Specific target organ toxicity - single exposure	STOT SE	3	H335

• Transport Information: UN 2810

Discovery and Applications

3-Acetylpyridine, with the molecular formula C7H7NO, is an organic compound that consists of a pyridine ring substituted with an acetyl group at the 3-position. It is a derivative of pyridine, a heterocyclic aromatic compound containing nitrogen. 3-Acetylpyridine is a colorless to pale yellow liquid at room temperature with a characteristic odor and has been widely used in various fields due to its chemical reactivity and functional properties.

The discovery of 3-acetylpyridine dates back to the early 20th century, following the exploration of pyridine derivatives for their potential applications in pharmaceuticals, agriculture, and synthetic chemistry. The compound is typically synthesized by acetylation of pyridine using acetic acid or acetic anhydride, catalyzed by a Lewis acid such as aluminum chloride. This reaction results in the introduction of the acetyl group at the 3-position of the pyridine ring, creating 3-acetylpyridine as a product. The compound can also be synthesized through other methods involving selective acylation or electrophilic substitution reactions.

3-Acetylpyridine has found a wide range of applications, particularly in the fields of organic synthesis, medicinal chemistry, and materials science. In organic synthesis, it serves as an important intermediate in the preparation of various complex molecules. The acetyl group at the 3-position of the pyridine ring offers a site for further functionalization, making it a versatile building block for the synthesis of pharmaceuticals, agrochemicals, and specialty chemicals. The compound’s reactivity allows it to participate in various types of chemical reactions, including nucleophilic substitution, reduction, and condensation reactions.

In medicinal chemistry, 3-acetylpyridine has attracted attention for its potential pharmacological properties. It has been investigated as a precursor for the synthesis of compounds with a range of biological activities, including antimicrobial, antifungal, and anti-inflammatory properties. One of the key uses of 3-acetylpyridine is in the synthesis of niacinamide (nicotinamide) derivatives, which are important in the field of dermatology for their ability to treat skin conditions such as acne and hyperpigmentation. Additionally, its derivatives have been studied for their potential as inhibitors of certain enzymes involved in cellular metabolism, with applications in the treatment of metabolic disorders and cancer.

3-Acetylpyridine is also used in the preparation of various coordination compounds, particularly in the development of metal-organic frameworks (MOFs) and other materials for applications in catalysis and sensing. The pyridine ring, which is a well-known ligand in coordination chemistry, allows 3-acetylpyridine to form stable complexes with metals such as copper, nickel, and palladium. These metal complexes have been explored for use in catalysis, particularly in reactions involving the activation of small molecules such as hydrogen and carbon dioxide. The incorporation of 3-acetylpyridine into MOFs also offers potential for applications in gas storage and separation, as well as in the development of sensors for detecting various environmental contaminants.

In the flavor and fragrance industry, 3-acetylpyridine has been studied for its role as a potential flavoring agent. The compound’s characteristic odor, which is described as somewhat nutty or tobacco-like, has led to its use in certain flavor formulations, particularly in the creation of savory or tobacco-like tastes. However, its use in this industry is less prevalent compared to other compounds with more desirable sensory properties.

In conclusion, 3-acetylpyridine is a versatile chemical with a wide range of applications in organic synthesis, medicinal chemistry, and materials science. Its ability to undergo various chemical reactions and its potential biological activities make it an important intermediate in the preparation of pharmaceuticals and agrochemicals. Ongoing research into its derivatives and metal complexes continues to expand its potential applications, highlighting the compound's significant value across diverse scientific and industrial fields.

References

2020. Functionalization of Pyridines. Synthesis, 52(18).
DOI: 10.1055/s-0040-1707890