Hydrolysis of Malonaldehyde Dianil and β-Arylaminoacrolein Derivatives

Abstract

The reversible hydrolysis of β-arylaminoacrolein to form arylamine and malonaldehyde was studied kinetically. The catalytic coefficient of hydronium ions (k^H+) and dissociation constant of the conjugate acid of β-arylaminoacrolein (K^BH+) were evaluated. Hammett plots for k^H+ and for K_BH+ were linear. The values of log k^H+ and pK^BH+ were expressed by the equations log k^H+=1.38σ-2.81 and pK_BH+=-1.20σ+0.90, respectively. The reversible hydrolysis of malonaldehyde dianil to form β-arylaminoacrolein and arylamine was examined in relation to that of β-arylaminoacrolein. The preparation of β-arylaminoacrolein by hydrolysis of malonaldehyde dianil was achieved under weakly acidic conditions.