Highly regioselective ortho-chlorination of phenol with sulfuryl chloride in the presence of amines

Article abstract of DOI:10.1016/0040-4039(95)00592-Z

Chlorination of phenol with sulfuryl chloride catalyzed by amines in non-polar solvents is fast, and specific for monochlorination and highly regioselective for ortho-substitution. Under optimal conditions, phenol was chlorinated with an equimolar quantity of sulfuryl chloride in the presence of di-s-butylamine (0.8 mole% relative to phenol) to give after 1 h of reaction at 70°C a 90.1% yield of ortho-chlorophenol with an ortho/para ratio of 22.0.