A process is provided for the preparation of the dimer, dichloro-[2,2]paracyclophane, which is useful as the starting material for the deposition of conformal parylene coatings employed, for example, in the electronics industry for the protection of various sensitive electronic components.The process avoids the normally low yields of chlorinated dimer formed by the chlorination of 2,2-paracyclophane and instead utilizes the Hofmann elimination of 2(3)-chloro-p-methylbenzyltrimethylammonium hydroxide by conducting the elimination reaction under carefully controlled conditions of reaction temperature and profile, reaction feed configuration, water concentration in the reactor and the use of a cosolvent, certain reaction promoters, or a combination thereof.