Provided are processes for the preparation of (S)-tert-butyl 4,5-diamino-5-oxopentanoate, or a salt, solvate, hydrate, enantiomer, mixture of enantiomers, or isotopologue thereof. Also provided are solid forms of various intermediates and products obtained from the processes.

Provided are processes for the preparation of (S)-tert-butyl 4,5-diamino-5-oxopentanoate, or a salt, solvate, hydrate, enantiomer, mixture of enantiomers, or isotopologue thereof. Also provided are solid forms of various intermediates and products obtained from the processes.

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. ##STR00001##

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. ##STR00001##

Provided are processes for the preparation of (S)-tert-butyl 4,5-diamino-5-oxopentanoate, or a salt, solvate, hydrate, enantiomer, mixture of enantiomers, or isotopologue thereof. Also provided are solid forms of various intermediates and products obtained from the processes.

Provided are processes for the preparation of (S)-tert-butyl 4,5-diamino-5-oxopentanoate, or a salt, solvate, hydrate, enantiomer, mixture of enantiomers, or isotopologue thereof. Also provided are solid forms of various intermediates and products obtained from the processes.

Provided is a metal complex as represented by formula I. The metal complex may be used as a catalyst for asymmetric catalytic hydrogenation, is capable of efficiently catalyzing and synthesizing a series of chiral p-aryl amides having high optical purity, and is especially capable of asymmetrically catalyzing and hydrogenating a tetra-substituted enamide compound, chiral amides having high optical purity are synthesized, and the carrying amount of ligand may reach 100,000.

##STR00001##

Provided is a metal complex as represented by formula I. The metal complex may be used as a catalyst for asymmetric catalytic hydrogenation, is capable of efficiently catalyzing and synthesizing a series of chiral p-aryl amides having high optical purity, and is especially capable of asymmetrically catalyzing and hydrogenating a tetra-substituted enamide compound, chiral amides having high optical purity are synthesized, and the carrying amount of ligand may reach 100,000.

##STR00001##

The present invention provides a novel method for the controlled stereoisomerization (comprising the stereo-conversion of chiral compounds to racemates, non-racemic mixtures and mixtures of epimers). The method of the invention provides the fully controlled generation of mixtures of different ratios of (S) and (R) stereoisomers, both enantiomers and diastereomers, of a given compound or a mixture of compounds. Such mixtures and isotopically labeled variants of said mixtures provided by the present invention are useful as an authenticity or external or internal standards in various biochemical and medical applications. Further, with the method of the invention it is possible to generate specific stereoisomers from some amino acids as well as degradation and oxidation products thereof which were previously not available. Thence, the invention provides in additional aspects the generation of a group of previously unavailable stereoisomers (enantiomers, epimers, and mixtures thereof such as a racemate) with amino acid type structures.

The present invention provides a novel method for the controlled stereoisomerization (comprising the stereo-conversion of chiral compounds to racemates, non-racemic mixtures and mixtures of epimers). The method of the invention provides the fully controlled generation of mixtures of different ratios of (S) and (R) stereoisomers, both enantiomers and diastereomers, of a given compound or a mixture of compounds. Such mixtures and isotopically labeled variants of said mixtures provided by the present invention are useful as an authenticity or external or internal standards in various biochemical and medical applications. Further, with the method of the invention it is possible to generate specific stereoisomers from some amino acids as well as degradation and oxidation products thereof which were previously not available. Thence, the invention provides in additional aspects the generation of a group of previously unavailable stereoisomers (enantiomers, epimers, and mixtures thereof such as a racemate) with amino acid type structures.