2-Chloropyridine

2-Chloropyridine

Names
Preferred IUPAC name 2-Chloropyridine
Identifiers
CAS Number	109-09-1 Y
3D model (JSmol)	Interactive image
Beilstein Reference	105788
ChEBI	CHEBI:39174 Y
ChEMBL	ChEMBL509579 Y
ChemSpider	7689 Y
ECHA InfoCard	100.003.316
EC Number	203-646-3
Gmelin Reference	130818
PubChem CID	7977
RTECS number	US5950000
UNII	8HMD45AYEJ Y
UN number	2822
CompTox Dashboard (EPA)	DTXSID8024810
InChI InChI=1S/C5H4ClN/c6-5-3-1-2-4-7-5/h1-4H Y Key: OKDGRDCXVWSXDC-UHFFFAOYSA-N Y InChI=1/C5H4ClN/c6-5-3-1-2-4-7-5/h1-4H Key: OKDGRDCXVWSXDC-UHFFFAOYAI
SMILES Clc1ncccc1
Properties
Chemical formula	C5H4ClN
Molar mass	113.54 g·mol−1
Appearance	colorless liquid
Density	1.2 g/mL
Melting point	−46 °C (−51 °F; 227 K)
Boiling point	166 °C (331 °F; 439 K)
Solubility in water	27 g/L
Acidity (pKa)	0.49 (for C5H4ClNH+)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H310, H315, H319, H330, H400
Precautionary statements	P260, P262, P264, P270, P271, P273, P280, P284, P301+P310, P301+P312, P302+P350, P302+P352, P304+P340, P305+P351+P338, P310, P311, P312, P314, P320, P321, P330, P332+P313, P337+P313, P361, P362, P363, P391, P403+P233, P405, P501
Safety data sheet (SDS)	MSDS
Related compounds
Related compounds	3-Chloropyridine 3-Bromopyridine 2-Chloromethylpyridine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

2-Chloropyridine is an organic compound with the fomula ClC₅H₄N. It is a colorless liquid that is mainly used to generate fungicides and insecticides in industry. It also serves to generate antihistamines and antiarrythymics for pharmaceutical purposes. It is one of three isomers of chloropyridine.

Preparation

2-Chloropyridine is produced by direct reaction of pyridine with chlorine.

Alternatively, 2-chloropyridines can be conveniently synthesized in high yields from pyridine-N-oxides.

2-Chloropyridine was originally prepared by the chlorination of 2-hydroxypyridine with phosphoryl chloride.

Main reactions and applications

2-Chloropyridine reacts further with chlorine to give 2,6-dichloropyridine.

2-Chloropyridine undergoes substitution at the C-Cl bond.

Some commercial products include pyrithione, pyripropoxyfen, chlorphenamine, and disopyramide. In these conversions, chloride is displaced. Pyrithione, the conjugate base of 2-mercaptopyridine-N-oxide, is a fungicide found in some shampoos. Oxidation 2-chloropyridine gives 2-chloropyridine-N-oxide. The antihistamine pheniramine may be generated via the reaction of phenylacetonitrile with 2-chloropyridine in the presence of a base.

Environmental properties

Although pyridine is an excellent source of carbon, nitrogen, and energy for certain microorganisms, introduction of a halogen moiety significantly retards degradation of the pyridine ring. With the exception of 4-chloropyridine, each of the mono- and di-substituted chloropyridines were found to be relatively resistant to microbiological degradation in soil or liquid media. Estimated time for complete degradation was > 30 days. 2-Chloropyridine exhibits extensive volatilization losses from water, less so when present in soil.

Toxicity

The LD₅₀ is 64 mg/kg (dermal, rabbit).

References