3-Chloropyridine is an aryl chloride and isomer of chloropyridine with the formula C<sub>5</sub>H<sub>4</sub>ClN. It is a colorless liquid that is mainly used as a building block in organic synthesis.
The compound is a substrate for many coupling processes including the Heck reaction, Suzuki reaction, and Ullmann reaction.
3-Chloropyridine may be prepared by the direct chlorination of pyridine with aluminium chloride used as the catalyst. The yield is 33%.
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. The process is thought to be an example of the CiamicianâÂÂDennstedt rearrangement.