Pyridine-4-carbaldehyde

Pyridine-4-carbaldehyde is an organic compound with the formula C₅H₄NCHO. It is one of three isomeric pyridinaldehydes. The other isomers are pyridine-2-carboxaldehyde and pyridine-3-carboxaldehyde. Pyridine-4-carboxaldehyde is a colorless liquid, although aged samples can appear yellow or even brown. It undergoes many reactions expected for aromatic aldehydes such as reductive amination and Schiff base formation.^[1] It condenses with pyrrole to give tetrapyridylporphyrin.^[2] The pKa has been experimentally determined by NMR spectroscopy to be 4.72.^[3]

Pyridine-4-carbaldehyde

Names
Preferred IUPAC name Pyridine-4-carbaldehyde
Other names 4-formylpyridine, 4-pyridinaldehyde, isonicotinaldehyde
Identifiers
CAS Number	872-85-5
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL2251606
ChemSpider	12816
ECHA InfoCard	100.011.666
EC Number	212-832-3
PubChem CID	13389
UNII	P577557492 Y
CompTox Dashboard (EPA)	DTXSID1061237
InChI InChI=1S/C6H5NO/c8-5-6-1-3-7-4-2-6/h1-5H Key: BGUWFUQJCDRPTL-UHFFFAOYSA-N
SMILES C1=CN=CC=C1C=O
Properties
Chemical formula	C6H5NO
Molar mass	107.112 g·mol−1
Appearance	colorless liquid
Melting point	4 °C (39 °F; 277 K)
Boiling point	198 °C (388 °F; 471 K)
Acidity (pKa)	4.72
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H317, H319, H335
Precautionary statements	P261, P264, P271, P272, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P333+P313, P337+P313, P362, P363, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references