The reaction of 2-amino-5-chlorobenzophenone (1) with 0•5-2 M HCl was studied in 1 : 1 (v/v) MeOH-H 2 O at 60 and 80 °C. Products that were isolated were characterized as 2-(N-methylamino-5-chlorobenzophenone (2), 2amino-3,5-dichlorobenzophenone (3), 2-N-methylamino-3,5-dichlorobenzophenone (4), 2-(N,N-dimethylamino-5chlorobenzophenone (5), 2,4-dichloro-10-methyl-9,10-acridinone (6) and 2,4-dichloro-9,10-acridinone (7). The rates of reaction of 1 and the rates of formation of 2-5 were measured at several HCl concentrations. The methyl transfers, the chlorination and the cyclization reactions that give rise to 2-7 were unexpected under the present reaction conditions. A set of differential equations was proposed in order to calculate the rate constants for each step of this complex reaction. The proposed reaction scheme also takes into account the reaction 2→1 and permits the calculation of the rate constants for this reversible reaction. The experimental values of the rate constants for reaction of 1 were compared with those for 2 under the same reaction conditions, in order to evaluate the importance of the methyl group on the methyl transfer reactions; it was found that the methyl group is not required for the unexpected reaction to occur.