NOVEL CRYSTAL FORMS OF 9-SUBSTITUTED HYPOXANTHINE DERIVATIVES

摘要

The bifunctional compound N-4-carboxyphenyl-3-(6-oxohydropurin-9-yl) propanamide monopotassium salt occurs in a number of crystal forms which differ in their stability. Of these forms, the most stable is designated Type I, which is a monopotassium salt monophydrate in which the water is held as water of crystallization. Other crystalline forms, designated Type II and Type III, convert to Type I. Methods are disclosed for the synthesis of Type I and for the conversion of Type II or Type III to Type I.