PROCESS FOR PREPARING INTERMEDIATE OF PITAVASTATIN OR ITS SALT

摘要

PURPOSE: A method for preparing pitavastatin or salt thereof is provided to avoid difficulty of handling intermediate compound of oil phase and to obtain a compound having dihydroxy moiety of high purity. CONSTITUTION: A method for preparing a compound of chemical formula 4 of solid crystal comprises: a step of reacting a compound of chemical formula 3 with a compound of chemical formula 2 under the presence of base; a step of adjusting the mixture at 40-45 °C; a step of adding alcohol of C1-C4 and cooling at 5-15 °C and precipitating; a step of washing precipitate with water and drying. A method for manufacturing pitavastatin or pharmaceutically acceptable salt thereof comprises: a step of preparing the compound of chemical formula 4; a step of adding acid to the compound of chemical formula 4; a step of converting to the compound of chemical formula 5; a step of NaOH to the compound of chemical formula 5; and a step of selectively converting pitavastatin free base to pharmaceutically acceptable salt.