HYDROLYTIC STABILITY OF IMIDES OF DIFFERENT STRUCTURES

The conversion kinetics of N(o-carboxyphenyl)naphthalimide has been studied in buffer solutions over a pH range 5-12.6 and temperature range 25-70 qc. The naphthalimide hydrolysis is shown to be a reversible reaction. The mechanism of the alkaline hydrolysis of N(o-carboxyphenyl) phthalimide is proposed. The structure dependence of the imide hydrolytic stability is explained on the basis of the suggested mechanism. Imldes are known to have low hydrolytic stability in alkaline media [1]. During multi step synthesis of polyisoindoloquinazolinedione the intermediate poly(o-carboxy)-imide is affected by NH3 and H 20 at high temperatures, which can induce polymer degradation. The influence of carboxyl group in 0-position to nitrogen of the imide cycle and naphthalene ring on the imide hydrolysis rate has been investigated by the example of model compounds. Experimental N-(o-carboxyphenyl)-phthalimide and its degradation product-N-phthalanthranilic acid-were prepared and purified according to know