Preparation of dichlorophene

An improvement in a process for the preparation of dichlorophene by reacting p-chlorophenol with formaldehyde in the presence of sulfuric acid. The improvement lies in contacting p-chlorophenol with the stoichiometric excess of formaldehyde in aqueous sulfuric acid by introducing into a sulfuric acid reaction medium 1 to 6% by weight of the total amount of p-chlorophenol to be reacted and thereafter adding the formaldehyde and additional p-chlorophenol to the reaction mixture in an amount such that at the end of the addition of the p-chlorophenol only 85 to 98% by weight of the total amount of formaldehyde has been added. The balance of the formaldehyde is then introduced into the reaction mixture.