3-Chloropyridine
{{Chembox
| ImageFile1 = 3-chloropyridine.svg
| ImageSize1 = 122
| ImageAlt1 =
| ImageFileL2 = 3-chloropyridine-from-xtal-3D-bs-17.png
| ImageFileR2 = 3-chloropyridine-from-xtal-3D-sf.png
| PIN = 3-Chloropyridine
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo = 626-60-8
| PubChem = 12287
| EC_number = 210-955-7
| UNII = 1M13HUC1P4
| ChemSpiderID = 11784
| StdInChI=1S/C5H4ClN/c6-5-2-1-3-7-4-5/h1-4H
| StdInChIKey = PWRBCZZQRRPXAB-UHFFFAOYSA-N
| SMILES = C1=CC(=CN=C1)Cl
}}
|Section2={{Chembox Properties
| C=5|H=4|Cl=1|N=1
| MolarMass =
| Appearance = colorless liquid
| Density = 1.194 g/cm3
| RefractIndex = 1.533
| MeltingPt =
| BoilingPtC = 148
| Solubility = }}
|Section3={{Chembox Hazards
| GHSPictograms = {{GHS02}}{{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|226|302|312|315|332}}
| PPhrases = {{P-phrases|210|233|240|241|242|243|261|264|270|271|280|301+312|302+352|303+361+353|304+312|304+340|312|321|322|330|332+313|362|363|370+378|403+235|501}}
| MainHazards =
| FlashPtC = 65
| AutoignitionPt = }}
| Section4 = {{Chembox Related
| OtherCompounds = 2-Chloropyridine
3-Bromopyridine
}}
}}
3-Chloropyridine is an aryl chloride and isomer of chloropyridine with the formula C5H4ClN. It is a colorless liquid that is mainly used as a building block in organic synthesis.{{Ullmann|first1=Shinkichi|last1=Shimizu|first2=Nanao|last2=Watanabe|first3=Toshiaki|last3=Kataoka|first4=Takayuki|last4= Shoji|first5=Nobuyuki|last5=Abe|first6=Sinji|last6=Morishita|first7=Hisao|last7=Ichimura|title=Pyridine and Pyridine Derivatives|year=2007|doi=10.1002/14356007.a22_399}}
The compound is a substrate for many coupling processes including the Heck reaction,{{cite journal |doi=10.1021/ja010988c|title=A Versatile Catalyst for Heck Reactions of Aryl Chlorides and Aryl Bromides under Mild Conditions|year=2001|last1=Littke|first1=Adam F.|last2=Fu|first2=Gregory C.|journal=Journal of the American Chemical Society|volume=123|issue=29|pages=6989–7000|pmid=11459477}} Suzuki reaction,{{cite journal |doi=10.1021/ja0002058|title=Versatile Catalysts for the Suzuki Cross-Coupling of Arylboronic Acids with Aryl and Vinyl Halides and Triflates under Mild Conditions|year=2000|last1=Littke|first1=Adam F.|last2=Dai|first2=Chaoyang|last3=Fu|first3=Gregory C.|journal=Journal of the American Chemical Society|volume=122|issue=17|pages=4020–4028}} and Ullmann reaction.{{cite journal |doi=10.1021/jo025619t|title=Highly Active Oxime-Derived Palladacycle Complexes for Suzuki−Miyaura and Ullmann-Type Coupling Reactions|year=2002|last1=Alonso|first1=Diego A.|last2=Nájera|first2=Carmen|last3=Pacheco|first3=M Carmen|journal=The Journal of Organic Chemistry|volume=67|issue=16|pages=5588–5594|pmid=12153256}}
Preparation
3-Chloropyridine may be prepared by the direct chlorination of pyridine with aluminium chloride used as the catalyst. The yield is 33%.{{cite journal |doi=10.1021/jo01062a036|title=The Swamping Catalyst Effect. III. The Halogenation of Pyridine and Picolines|year=1961|last1=Pearson|first1=D. E.|last2=Hargrove|first2=W. W.|last3=Chow|first3=Judith K. T.|last4=Suthers|first4=B. R.|journal=Journal of the American Chemical Society|volume=26|issue=3|pages=790–791}}
A less expensive way of preparing 3-chloropyridine consists of the gas phase pyrolysis of a mixture of pyrrole and chloroform in an empty glass tube. The molar ratio of the reagents is one to five. The yields range from 25 to 33%. A little 2-chloropyridine is formed as a side product.{{cite journal |doi=10.1021/ja01622a077|title=An Improved Synthesis for 3-Chloropyridine|year=1955|last1=Rice|first1=H. L.|last2=Londergan|first2=T. E.|journal=Journal of the American Chemical Society|volume=77|issue=17|page=4678}} The process is thought to be an example of the Ciamician–Dennstedt rearrangement.
:File:3-Chloropyridine synthesis via pyrolysis.png{{clear-left}}
References
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{{DEFAULTSORT:Chloropyridine, 3-}}