- Preparation methods of aprepitant impurity
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The invention discloses preparation methods of an aprepitant impurity, which comprise isomer impurity synthesis method of six aprepitant key intermediates (2R, 3S)-2-[(1R)-1-[3, 5-bis (trifluoromethyl)-phenyl] ethoxy]-3-(4-fluorophenyl) morpholine, respectively, synthesis of four diastereomer impurities, synthesis of one enantiomer impurity and synthesis of one by-product impurity. The methods have the beneficial effects that the five synthesis methods are simple and feasible, the raw materials are easy to obtain, the conditions are mild, the cost is low, the production is facilitated, and meanwhile, the isomer impurities of the synthesized aprepitant key intermediate provide a new intermediate raw material for the preparation of aprepitant.
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- Practical asymmetric synthesis of aprepitant, a potent human NK-1 receptor antagonist, via a stereoselective Lewis acid-catalyzed trans acetalization reaction
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A streamlined and high-yielding synthesis of aprepitant (1), a potent substance P (SP) receptor antagonist, is described. The enantiopure oxazinone 16 starting material was synthesized via a novel crystallization-induced dynamic resolution process. Conversion of 16 to the penultimate intermediate cis-sec-amine 9 features a highly stereoselective Lewis acid-catalyzed trans acetalization of chiral alcohol 3 with trichloroacetimidate 18 followed by inversion of the adjacent chiral center on the morpholine ring. The six-step process for the synthesis of 9 was accomplished in extremely high overall yield (81%) and with only two isolations.
- Zhao, Matthew M.,McNamara, James M.,Ho, Guo-Jie,Emerson, Khateeta M.,Song, Zhiguo J.,Tschaen, David M.,Brands, Karel M. J.,Dolling, Ulf-H,Grabowski, Edward J. J.,Reider, Paul J.,Cottrell, Ian F.,Ashwood, Michael S.,Bishop, Brian C.
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p. 6743 - 6747
(2007/10/03)
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