NOVEL CRYSTALLINE FORM OF 5-(4-((3-METHYL-4-OXO-3,4-DIHYDROQUINAZOLIN-2-YL)METHOXY)BENZYL)THIAZOLIDINE-2,4-DIONE POTASSIUM SALT

摘要

A process for preparing polymorphic Form I of 5-[4-[[3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl]methoxy]benzyl]thiazolidine-2,4-dione potassium salt having the formula:
and characterized by having a differential scanning calorimetry curve with endotherms at 301.17 and 311.82°C and an exotherm at 297.68°C, comprising: (i) dissolving 5-[4-[[3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl]methoxy]benzyl]thiazolidine-2,4-dione in an organic solvent at 60-80°C; (ii) adding a solution of potassium tertiary butoxide, at 40-60°C; (iii) stirring at a temperature of 20-90°C; and (iv) cooling, separating a precipitate and drying under vacuum at 40-70°C.