The present invention provides a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Adopting a particular isomerization-crystallization condition makes it possible to a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Additionally, an intermediate efficacious for producing lacosamide is provided.

The present invention provides a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Adopting a particular isomerization-crystallization condition makes it possible to a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Additionally, an intermediate efficacious for producing lacosamide is provided.

Provided is a method for producing an optically active substance, the method including an asymmetric induction, wherein an asymmetry inducer is allowed to act on a chiral molecule having a half-life of enantiomeric excess of shorter than 10 hours, thereby increasing abundance of one enantiomer of the chiral molecule. According to this method, one enantiomer of a chiral molecule that is susceptible to racemization can be selectively and efficiently obtained.

Provided is a method for producing an optically active substance, the method including an asymmetric induction, wherein an asymmetry inducer is allowed to act on a chiral molecule having a half-life of enantiomeric excess of shorter than 10 hours, thereby increasing abundance of one enantiomer of the chiral molecule. According to this method, one enantiomer of a chiral molecule that is susceptible to racemization can be selectively and efficiently obtained.

The present invention provides a process for preparing 2-methyl-N-(2-methylbutyl)butanamide of the following formula (1): the process comprising: subjecting an ?-arylethyl-2-methylbutylamine compound of the following general formula (2): wherein Ar represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, to N-2-methylbutyrylation to form an N-?-arylethyl-2-methyl-N-(2-methylbutyl)butanamide compound of the following general formula (3): wherein Ar is as defined above, and removing the ?-arylethyl group of the resulting compound (3) to form 2-methyl-N-(2-methylbutyl)butanamide (1). ##STR00001##

The present invention provides a process for preparing 2-methyl-N-(2-methylbutyl)butanamide of the following formula (1): the process comprising: subjecting an ?-arylethyl-2-methylbutylamine compound of the following general formula (2): wherein Ar represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, to N-2-methylbutyrylation to form an N-?-arylethyl-2-methyl-N-(2-methylbutyl)butanamide compound of the following general formula (3): wherein Ar is as defined above, and removing the ?-arylethyl group of the resulting compound (3) to form 2-methyl-N-(2-methylbutyl)butanamide (1). ##STR00001##

The present invention provides a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Adopting a particular isomerization-crystallization condition makes it possible to a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Additionally, an intermediate efficacious for producing lacosamide is provided.

The present invention provides a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Adopting a particular isomerization-crystallization condition makes it possible to a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Additionally, an intermediate efficacious for producing lacosamide is provided.

The present invention provides a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Adopting a particular isomerization-crystallization condition makes it possible to a method of industrially and safely producing lacosamide high in diastereomeric excess at a high yield and a low cost. Additionally, an intermediate efficacious for producing lacosamide is provided.

A core-shell nanocomposite is formed by co-assembly of an amphiphilic polymer and hydrophobically modified magnetic nanoparticles, with its core being a hydrophobically modified magnetic nanomaterial and its shell being the amphiphilic polymer, wherein hydrophilic segments in the amphiphilic polymer are located at an outermost layer of the shell. The above composite can be used as additives in the crystallization of conglomerates and obtain optically pure crystals of both enantiomers in a single process. The key thereof is that the composite is used to enrich molecules with the same configuration while inhibit the crystallization of the other enantiomer in a supersaturated solution of conglomerates, such that a non-magnetic crystal and a magnetic crystal (which are enantiomers of each other) are generated in a unit operation. Optically pure crystals of both enantiomers with over 90 ee % can be obtained by one-time crystallization, and the total yield can be as high as 40%.