IMPROVED PROCESS TO PREPARE S-2-HYDROXY-3-METHOXY-3,3-DIPHENYL PROPIONIC ACID

摘要

Disclosed is a process for the preparation of S-2-Hydroxy-3-methoxy-3,3-diphenylpropionic acid (I) the key intermediate for the preparation of Ambrisentan [(+)-2(S)-(4,6-Dimethylpyrimidin-2-yloxy)-3-methoxy-3,3-diphenylpropionic acid]. Ambrisentan of the formula (IA) is approved under the trademark "Letairis ®" by the US Food and Drug Administration for the treatment of Pulmonary artery hypertension(PAH).