The present invention relates to a method for the racemization of enantiomerically pure or enantiomerically enriched Praziquantel under basic conditions and a method for the production of (R)-Praziquantel in enantiopure or enantiomerically enriched form, which comprises the racemization method.

The present invention relates to a method for the racemization of enantiomerically pure or enantiomerically enriched Praziquantel under basic conditions and a method for the production of (R)-Praziquantel in enantiopure or enantiomerically enriched form, which comprises the racemization method.

The present invention relates to a novel process for the preparation of pantolactone by reaction of hydroxypivalaldehyde cyanohydrin in a phase separation process.

The present invention relates to a novel process for the preparation of pantolactone by reaction of hydroxypivalaldehyde cyanohydrin in a phase separation process.

The present invention relates to compounds useful as pharmaceutical intermediates, to processes for preparing the intermediates, to intermediates used in the processes, and to the use of the intermediates in the preparation of pharmaceuticals. In particular, the present invention concerns enantiomerically pure optionally substituted 2-(1-hydroxy-alkyl)-chromen-4-one derivatives represented by formula (IA) and (IB), processes for preparing the alcohol derivatives and their use in preparing pharmaceuticals.

The present invention relates to compounds useful as pharmaceutical intermediates, to processes for preparing the intermediates, to intermediates used in the processes, and to the use of the intermediates in the preparation of pharmaceuticals. In particular, the present invention concerns enantiomerically pure optionally substituted 2-(1-hydroxy-alkyl)-chromen-4-one derivatives represented by formula (IA) and (IB), processes for preparing the alcohol derivatives and their use in preparing pharmaceuticals.

Provided is a method for producing an optically active carboxylic acid ester at a high yield and with high enantioselectivity using dynamic kinetic resolution, said optically active carboxylic acid ester having an -nitrogen substituent. This method for producing an optically active carboxylic acid ester includes a step in which racemic carboxylic acid represented by formula (a) and a specific alcohol or phenol derivative are reacted in a polar solvent having a dipole moment of at least 3.5 in the presence of an acid anhydride and an asymmetric catalyst, one enantiomer of the racemic carboxylic acid is selectively esterified, and the other enantiomer is racemized. In formula (a), Ra1 represents a nitrogen-containing heteroaromatic ring group bonded to an assymetric carbon via a nitrogen atom constituting a ring, and Ra2 is an organic group.

Provided is a method for producing an optically active carboxylic acid ester at a high yield and with high enantioselectivity using dynamic kinetic resolution, said optically active carboxylic acid ester having an -nitrogen substituent. This method for producing an optically active carboxylic acid ester includes a step in which racemic carboxylic acid represented by formula (a) and a specific alcohol or phenol derivative are reacted in a polar solvent having a dipole moment of at least 3.5 in the presence of an acid anhydride and an asymmetric catalyst, one enantiomer of the racemic carboxylic acid is selectively esterified, and the other enantiomer is racemized. In formula (a), Ra1 represents a nitrogen-containing heteroaromatic ring group bonded to an assymetric carbon via a nitrogen atom constituting a ring, and Ra2 is an organic group.

The present invention is characterized in that racemic or optically active D- or L--glycerophosphoryl choline solids are prepared from liquid type racemic or optically active D- or L--glycerophosphoryl choline using an organic solvent. The present invention can produce solids at a high yield more easily through phase transformation rather than a method using a difference in solubility in a solvent, which is an existing method.

The present invention is characterized in that racemic or optically active D- or L--glycerophosphoryl choline solids are prepared from liquid type racemic or optically active D- or L--glycerophosphoryl choline using an organic solvent. The present invention can produce solids at a high yield more easily through phase transformation rather than a method using a difference in solubility in a solvent, which is an existing method.