KINETIC-STUDY OF THE REACTIONS OF 2-AMINO-5-CHLOROBENZOPHENONE WITH HCL IN MEOH-H2O

The reaction of 2-amino-5-chlorobenzophenone (1) with 0.5-2 M HCl was studied in 1:1 (v/v) MeOH-H2O at 60 and 80 degrees C, Products that we re isolated were characterized as 2-(N-methylamino-5-chlorobenzophenon e (2), 2-amino-3,5-dichlorobenzophenone (3), 2-N-methylamino-3,5-dichl orobenzophenone (4), 2-(N,N-dimethylamino-5-chlorobenzophenone (5), 2, 4-dichloro-10-methyl-9,10-acridinone (6) and 2,4-dichloro-9,10-acridin one (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 differenti al 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 valu es of the rate constants for reaction of 1 were compared with those fo r 2 under the same reaction conditions, in order to evaluate the impor tance of the methyl group on the methyl transfer reactions; it was fou nd that the methyl group is not required for the unexpected reaction t o occur. (C) 1997 by John Wiley & Sons, Ltd.