Abstract: The present invention relates to a process for preparing 2,6-dichloropyridine which comprises reacting an organic solvent-free, catalyst-free reaction mixture comprising 2-chloropyridine and chlorine in the presence of a hydrogen chloride scavenger and ultraviolet light, and optionally in the presence of added moisture, at a temperature of between about 90.degree. C. and about 185.degree. C. Also claimed is a method for preventing calcium chloride plugging of the chlorine feed stream and for preventing calcium chloride build-up in the above reaction mixture which comprises adding moisture in the form of water or steam, or a combination thereof, to the reaction mixture prior to, or during, the reaction of said process.