3-Pyridinecarboxaldehyde
[CAS# 500-22-1]

Identification

• Classification: Chemical pesticide >> Insecticide intermediate
• Name: 3-Pyridinecarboxaldehyde
• Synonyms: Nicotinaldehyde; Pyridine-3-carboxaldehyde
• Molecular Formula: C₆H₅NO
• Molecular Weight: 107.11
• CAS Registry Number: 500-22-1
• EC Number: 207-900-4
• SMILES: C1=CC(=CN=C1)C=O

Properties

• Density: 1.1±0.1 g/cm³ Calc.^*, 1.145 g/mL (Expl.)
• Melting point: 8 °C (Expl.)
• Boiling point: 209.9 °C 760 mmHg (Calc.)^*, 221.4 - 225.5 °C (Expl.)
• Flash point: 60.0 °C (Calc.)^*, 60 °C (Expl.)
• Solubility: water: miscible (Expl.)
• Index of refraction: 1.573 (Calc.)^*, 1.549 (Expl.)

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

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS07;GHS08 Danger
• Risk Statements: H226-H302-H315-H317-H318-H334-H335-H341-H412
• Safety Statements: P203-P210-P233-P240-P241-P242-P243-P260-P261-P264-P264+P265-P270-P271-P272-P273-P280-P284-P301+P317-P302+P352-P303+P361+P353-P304+P340-P305+P354+P338-P317-P318-P319-P321-P330-P332+P317-P333+P317-P342+P316-P362+P364-P370+P378-P403-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Flammable liquids	Flam. Liq.	3	H226
Serious eye damage	Eye Dam.	1	H318
Skin sensitization	Skin Sens.	1	H317
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Respiratory sensitization	Resp. Sens.	1	H334
Germ cell mutagenicity	Muta.	2	H341
Skin sensitization	Skin Sens.	1B	H317
Flammable liquids	Flam. Liq.	4	H227
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

3-Pyridinecarboxaldehyde is an aromatic heterocyclic compound consisting of a pyridine ring substituted at the third position with an aldehyde functional group. Its molecular formula is C₆H₅NO, and it is also known as nicotinaldehyde. The compound belongs to the class of pyridine derivatives, which are widely studied and utilized in organic synthesis, pharmaceuticals, and coordination chemistry.

3-Pyridinecarboxaldehyde can be synthesized through several methods, including the oxidation of 3-methylpyridine (3-picoline) using oxidizing agents such as selenium dioxide or chromium-based reagents under controlled conditions. Alternative synthetic approaches involve formylation reactions of pyridine derivatives, such as the Reimer-Tiemann reaction or Vilsmeier-Haack formylation, enabling selective introduction of the aldehyde group at the 3-position.

This compound serves as a versatile building block in organic synthesis due to the presence of both the aromatic heterocycle and the reactive aldehyde functional group. The aldehyde moiety undergoes various typical carbonyl reactions, including nucleophilic additions, condensations, and oxidations, allowing for the construction of a wide range of substituted pyridine derivatives.

3-Pyridinecarboxaldehyde is extensively employed in the synthesis of pharmaceuticals, agrochemicals, and fine chemicals. Its reactivity facilitates the formation of Schiff bases, hydrazones, and heterocyclic compounds, which serve as intermediates in the preparation of drugs and biologically active molecules. The pyridine ring imparts favorable properties such as basicity, coordination ability, and metabolic stability to the resulting compounds.

In coordination chemistry, 3-pyridinecarboxaldehyde acts as a ligand or precursor to ligands that coordinate to metal centers through the nitrogen atom of the pyridine ring and the aldehyde functional group or its derivatives. Such complexes have applications in catalysis, materials science, and medicinal chemistry.

Physically, 3-pyridinecarboxaldehyde is typically a colorless to pale yellow liquid or crystalline solid, depending on purity and storage conditions. It is soluble in common organic solvents such as ethanol, ether, and chloroform, with moderate polarity due to the aldehyde group and aromatic nitrogen.

The compound should be handled with care as aldehydes can be irritant and potentially sensitizing. It is sensitive to oxidation and polymerization under certain conditions, so it is recommended to store it in a cool, dark place, often with stabilizers or under inert atmosphere.

In summary, 3-pyridinecarboxaldehyde is a valuable aromatic heterocyclic aldehyde widely used as an intermediate in organic synthesis, pharmaceuticals, and coordination chemistry. Its combination of pyridine ring and aldehyde functionality enables diverse chemical transformations and applications in multiple scientific and industrial fields.

References

2025. Synthesis, Photophysical Properties and Antioxidant Activity of Novel Quinoline Derivatives. Journal of Fluorescence, 35(1).
DOI: 10.1007/s10895-023-03519-2

2024. Investigation of the electrochemical conversion of brighteners during nickel electrodeposition, Part 1: chemical analysis by mass spectrometry. Journal of Applied Electrochemistry, 54(11).
DOI: 10.1007/s10800-024-02208-7

2023. Pyridinecarboxaldehydes: Structures, Vibrational Assignments and Molecular Characteristics Using Experimental and Theoretical Methods. Brazilian Journal of Physics, 53(2).
DOI: 10.1007/s13538-023-01255-3