2-Chloromethylpyridine
{{Chembox
| ImageFile = 2-Chloromethylpyridine.svg
| ImageSize = 100
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| PIN = 2-(Chloromethyl)pyridine
| OtherNames = 2-Picolinyl chloride; 2-Picolyl chloride
| Section1 = {{Chembox Identifiers
| CASNo = 4377-33-7
| ChEBI = 76601
| ChEMBL = 1620152
| ChemSpiderID = 21875
| PubChem = 23393
| UNII = 59YW2EH117
| StdInChI=1S/C6H6ClN/c7-5-6-3-1-2-4-8-6/h1-4H,5H2
| StdInChIKey = NJWIMFZLESWFIM-UHFFFAOYSA-N
| SMILES = C1=CC=NC(=C1)CCl
}}
| Section2 = {{Chembox Properties
| C=6|H=6|N=1|Cl=1
| MolarMass =
| Appearance = white solid
| Density =
| MeltingPtC = 79
| BoilingPt =
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| Section3 = {{Chembox Hazards
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| Section7 = {{Chembox Hazards
| NFPA-H =
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| GHSPictograms = {{GHS05}} {{GHS07}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|302|314}}
| PPhrases = {{P-phrases|260|264|270|280|301+312+330|301+330+331|310|363|405|501}}
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2-Chloromethylpyridine is an organohalide that consists of a pyridine core bearing a chloromethyl group. It is one of three isomeric chloromethylpyridines, along with 3- and 4-chloromethylpyridine. It is an alkylating agent.
Preparation and reactions
It can be prepared by reaction of 2-methylpyridine with chlorine. A more efficient route involves treating 2-picoline-N-oxide with phosphoryl chloride in the presence of triethylamine:{{cite journal |doi=10.1002/jhet.5570180518 |title=The Synthesis of 2-Chloromethylpyridine from 2-Picoline-N-Oxide |date=1981 |last1=Ash |first1=Mary Lynne |last2=Pews |first2=R. Garth |journal=Journal of Heterocyclic Chemistry |volume=18 |issue=5 |pages=939–940 }}
:{{chem2|CH3C5H4NO + POCl3 + Et3N -> ClCH2C5H4N + Et3NH+[PO2Cl2]-}} (Et = C2H5)
A related method uses triphosgene in place of phosphoryl chloride.{{cite journal |doi=10.1081/SCC-120028642 |title=Facile and Selective Synthesis of Chloromethylpyridines and Chloropyridines Using Diphosgene/Triphosgene |date=2004 |last1=Narendar |first1=P. |last2=Gangadasu |first2=B. |last3=Ramesh |first3=Ch. |last4=China Raju |first4=B. |last5=Jayathirtha Rao |first5=V. |journal=Synthetic Communications |volume=34 |issue=6 |pages=1097–1103 }}
2-Chloromethylpyridine is a precursor to pyridine-containing ligands.{{cite journal |doi=10.1021/acs.organomet.0c00717|title=Cationic PCP and PCN NHC Core Pincer-Type Mn(I) Complexes: From Synthesis to Catalysis|year=2021|last1=Buhaibeh|first1=Ruqaya|last2=Duhayon|first2=Carine|last3=Valyaev|first3=Dmitry A.|last4=Sortais|first4=Jean-Baptiste|last5=Canac|first5=Yves|journal=Organometallics|volume=40|issue=2|pages=231–241|s2cid=234156476 |url=https://hal.archives-ouvertes.fr/hal-03128570 }}{{cite journal |doi=10.1021/ic00062a047|title=Chelating Properties of 2-((Diphenylphosphino)methyl)pyridine N,P-dioxide and 2,6-Bis((diphenylphosphino)methyl)pyridine N,P,P{{'}}-trioxide Toward f-Element Ions|year=1993|last1=Rapko|first1=B. M.|last2=Duesler|first2=E. N.|last3=Smith|first3=P. H.|last4=Paine|first4=R. T.|last5=Ryan|first5=R. R.|journal=Inorganic Chemistry|volume=32|issue=10|pages=2164–2174}}
Safety
2-Chloromethylpyridine is an analogue of nitrogen mustards, and has been investigated for its mutagenicity.{{fact|date=August 2022}}