Process for the preparation of (S)-alpha-ethyl-2-oxo-1-pyrrolidineacetamide and (R)-alpha-ethyl-2-oxo-pyrrolidineacetamide
申请人:Apotex Pharmachem Inc.
公开号:US07902380B2
公开(公告)日:2011-03-08
A process provided for the preparation of the (S)- and (R)- alpha- ethyl-2-oxo-1-pyrrolidineacetamide of formula:(1) from (RS)-alpha-ethyl-2-oxo-1-pyrrolidineacetic acid of formula:(2) comprising: i) combining the (RS)-2 with a chiral base (resolving agent) in a resolution solvent and crystallizing from the said mixture the diastereomeric salt of (S)- or (R)-2 and chiral base; ii) regenerating (S)- or (R)-2 from the crystallized diastereomeric salt by treating with a suitable acid or acidic ion-exchange resin; iii) optionally regenerating (R)- or (S)-2 or their mixture (predominantly one enantiomer) from the crystallization mother liquor by treating with a suitable acid or acidic ion-exchange resin; iv) optionally epimerizing (RS)-2 by treating (R)- or (S)-2 or their mixture (predominantly one enantiomer) of step iii with an acid anhydride; V) optionally converting (RS)-2 of step iv into enantiomerically enriched (S)- or (R)-2 through steps i and ii; vi) formation of the mixed anhydride by reacting (R)- or (S)-2 with an alkyl or aryl sulfonyl halogen compound RSO2X in the presence of a suitable base; and vii) reacting the mixed anhydride with ammonia; wherein R represents C 1 to C 15 alkyl or aryl groups such as methyl, ethyl, p-toluenyl, 2,4,6-trimethylbenzyl, 2,4,6-trichloribenzyl, and X represents a halogen atom such as F, Cl and Br atoms.
提供了一种从式(2)的(RS)-α-乙基-2-氧代-1-吡咯烷乙酸制备式(1)的(S)-和(R)-α-乙基-2-氧代-1-吡咯乙酰胺的方法,包括:i)在分辨剂溶剂中将(RS)-2与手性碱(分辨剂)结合,并从所述混合物中结晶出(S)-或(R)-2和手性碱的对映异构盐;ii)通过使用适当的酸或酸性离子交换树脂处理结晶出的对映异构盐来再生(S)-或(R)-2;iii)通过使用适当的酸或酸性离子交换树脂,可选地再生(S)-或(R)-2或它们的混合物(主要是一种对映体)从结晶母液中;iv)通过使用酸酐处理步骤iii中的(R)-或(S)-2或它们的混合物(主要是一种对映体)可选地使(RS)-2外消旋化;v)通过步骤i和ii将步骤iv中的(RS)-2转化为对映富集的(S)-或(R)-2;vi)在适当的碱存在下,通过将(R)-或(S)-2与烷基或芳基磺酰卤化物RSO2X反应形成混合酐;vii)用氨反应混合酐;其中R代表C1到C15的烷基或芳基基团,例如甲基、乙基、对甲苯基、2,4,6-三甲基苯基、2,4,6-三氯苯基,X代表氟、氯和溴原子。