he Reaction Rate of Phithalic Anhydride With Urea in the Presence of Acetic Acid From the Freezing Curve

Antranilic acid is an intermediate material which we
can produce by Hofmann's rearrangement reaction. In
this process phithalimide is a main reactant. One
procedure for produceing phthalimide is the reaction of
phithalic anhydride with urea in the presence of acetic
acid. In this research, the kinetics of this reaction was
studied at 115 C. We found that the reaction of phthalic
anhydride and urea is a second order reaction. The rate
constant was 0.OS1 liter/mole minute.
In determining the rate constant, the freezing curve
for the binary mixture of phthalimide and phthalic
anhydride was also obtained. It was found that the
optimum initial ratio of urea to phthalic anhydride is in the range of 1-2.