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.