Abstract: The present invention relates to a brivaracetam intermediate, a preparation method therefor, and a preparation method for brivaracetam. The steps of the method for preparing brivaracetam described in the present invention are short and the raw materials are cheap, moreover, the method is simple and highly effective without requiring isomer separation by means of column chromatography or asymmetric synthesis, being suitable for industrial large-scale production. In addition, disclosed by the present invention is a compound as shown in formula (II), which may be used for the synthesis of brivaracetam.

Abstract: The present invention relates to a brivaracetam intermediate, a preparation method therefor, and a preparation method for brivaracetam. The steps of the method for preparing brivaracetam described in the present invention are short and the raw materials are cheap, moreover, the method is simple and highly effective without requiring isomer separation by means of column chromatography or asymmetric synthesis, being suitable for industrial large-scale production. In addition, disclosed by the present invention is a compound as shown in formula (II), which may be used for the synthesis of brivaracetam.

Abstract: The present invention relates to an asymmetric synthesis method of a chiral intermediate (S,S)-2,8-diazabicyclo[4,3,0]nonane (I) of moxifloxacin, wherein an imide or enamine compound is obtained by dehydration reaction of the pyrrolidine-3-ketone as shown in formula (II) and chiral amine(R)-1-phenylethylamine, followed by the reduction of the imide or enamine compound to obtain a compound of formula (III) or (IV) having the chiral structure of formula (I), and then a compound of formula (I) is obtained by intramolecular cyclization, and removal of the chiral auxiliary group and amino-protecting group. The present invention also relates to pyrrolidine-3-ketone as shown in formula (II) and a preparation method therefor, and in the formula (I), (II), (III), (IV), R is an amino-protecting group, especially C1-4 alkoxycarbonyl, benzyloxycarbonyl or benzyl which can be removed by hydrolysis or hydrogenation.

Abstract: The present invention relates to an asymmetric synthesis method of a chiral intermediate (S,S)-2,8-diazabicyclo[4,3,0]nonane (I) of moxifloxacin, wherein an imide or enamine compound is obtained by dehydration reaction of the pyrrolidine-3-ketone as shown in formula (II) and chiral amine(R)-1-phenylethylamine, followed by the reduction of the imide or enamine compound to obtain a compound of formula (III) or (IV) having the chiral structure of formula (I), and then a compound of formula (I) is obtained by intramolecular cyclization, and removal of the chiral auxiliary group and amino-protecting group. The present invention also relates to pyrrolidine-3-ketone as shown in formula (II) and a preparation method therefor, and in the formula (I), (II), (III), (IV), R is an amino-protecting group, especially C1-4 alkoxycarbonyl, benzyloxycarbonyl or benzyl which can be removed by hydrolysis or hydrogenation.