The present invention provides a process for the preparation of 5-[[(2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(4-fluorophenyl)-4-morpholinyl]methyl]-1,2-dihydro-3H-1,2,4-triazole-3-one (Aprepitant) comprising condensation of 2-(R)-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(S)-(4-fluorophenyl)morpholine hydrochloride salt with 2-(2-chloro-1-iminoethyl)hydrazinecarboxylic acid methyl ester to obtain the reaction mixture containing 2-[2-[(2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(4-fluorophenyl)-4-morpholinyl]-1-iminoethyl]hydrazinecarboxylic acid methyl ester, which is in-situ cyclized in the presence of dimethylsulfoxide and a polar protic solvent at a low temperature to yield aprepitant having purity ≧99.5%.
本发明提供一种制备阿普利匹汀的方法,包括将2-(R)-[(1R)-1-[3,5-双(三
氟甲基)苯基]乙氧基]-3-(S)-(4-
氟苯基)
吗啡啶盐酸盐与2-(2-
氯-1-亚甲基)
肼基
乙酸甲酯缩合,得到反应混合物,其中包含2-[2-[(2R,3S)-2-[(1R)-1-[3,5-双(三
氟甲基)苯基]乙氧基]-3-(4-
氟苯基)-4-
吗啡啶基]-1-亚甲基]
肼基
乙酸甲酯,该物质在
二甲基亚砜和极性质子溶剂的低温存在下原位环化,生成纯度≧99.5%的阿普利匹汀。