The present invention relates to a process for the preparation of (S) -2-methoxy-3- {4- [2- (5-methyl-2- phenyl- oxazol- 4- yl) -ethoxy] Yl} -propionic acid and (S) -2-methoxy-3- {4- [2- (5-methyl-2- phenyl- oxazol- 7-yl} -propionic acid. <; / RTI >;본 발명은 (S)-2-메톡시-3-{4-[2-(5-메틸-2-페닐-옥사졸-4-일)-에톡시]-벤조[b]티오펜-7-일}-프로피온산 및 (S)-2-메톡시-3-{4-[2-(5-메틸-2-페닐-옥사졸-4-일)-에톡시]-벤조[b]티오펜-7-일}-프로피온산의 염의 고체 형태에 관한 것이다.