It chlorinates allylic and benzylic CH bonds. Electrochlorination chlorinates drinking water and does so in an Eco-friendly way. Electrochlorination chlorinates water in an Eco-friendly manner. It also chlorinates alkanes, alkenes, alkynes, aromatics, ethers (such as tetrahydrofuran) and epoxides. The resulting phenol sulfonic acid chlorinates at the positions flanking the phenol. Saponification followed by treatment with thionyl chloride then chlorinates the primary alcohol (5).