Polyhalogeno-aromatic compounds. Part XXVI. Photochemistry of pentachloropyridine and some derivatives

Abstract

Irradiation of pentachloropyridine in cyclohexane, diethyl ether, or dioxan gave 2,3,4,6-tetrachloropyridine, whereas in benzene tetrachloro-3-phenylpyridine was obtained. Irradiation of pentachloropyridine 1-oxide in carbon tetrachloride gave pentachlorobutadienyl isocyanate. Irradiation of tetrachloro-N-methyl-2-pyridone gave tetra-chloro-2-methyl-2-azabicyclo[2.2.0]hex-5-en-3-one. Some nucleophilic substitutions in 2,3,4,6-tetrachloro-pyridine are also described.