The present disclosure relates to the field of medicine synthesis, and relates to a method for a racemic preparation of chiral h β-amino acids and derivatives thereof, and in particular to a method for racemizing sitagliptin intermediates.

##STR00001##

where R.sub.1 is hydrogen, alkyl or aryl; R.sub.2 is hydrogen, alkyl or aryl; R.sub.3 is hydrogen, alkyl, aryl or acyl; R.sub.4 is alkyl, aryl, OR′, SR′, NHR′ or NR′R″, wherein R′, R″ are hydrogen, alkyl or aryl.

The present disclosure relates to the field of medicine synthesis, and relates to a method for a racemic preparation of chiral h β-amino acids and derivatives thereof, and in particular to a method for racemizing sitagliptin intermediates.

##STR00001##

where R.sub.1 is hydrogen, alkyl or aryl; R.sub.2 is hydrogen, alkyl or aryl; R.sub.3 is hydrogen, alkyl, aryl or acyl; R.sub.4 is alkyl, aryl, OR′, SR′, NHR′ or NR′R″, wherein R′, R″ are hydrogen, alkyl or aryl.

The present disclosure relates to the field of medicine synthesis, and relates to a method for a racemic preparation of chiral h β-amino acids and derivatives thereof, and in particular to a method for racemizing sitagliptin intermediates.

##STR00001##

where R.sub.1 is hydrogen, alkyl or aryl; R.sub.2 is hydrogen, alkyl or aryl; R.sub.3 is hydrogen, alkyl, aryl or acyl; R.sub.4 is alkyl, aryl, OR′, SR′, NHR′ or NR′R″, wherein R′, R″ are hydrogen, alkyl or aryl.

A process for making a complexing agent with an enantiomeric excess of at least 60%, wherein said process comprises the following steps: (a) reacting an aqueous slurry of alanine with an enantiomeric excess of at least 60% with formaldehyde and hydrocyanic acid, thereby forming an aqueous solution of alanine-bisacetonitrile, (b) saponifying the alanine-bisacetonitrile from step (a) by combining the aqueous solution obtained in step (a) with an aqueous solution of alkali metal hydroxide.

A process for making a complexing agent with an enantiomeric excess of at least 60%, wherein said process comprises the following steps: (a) reacting an aqueous slurry of alanine with an enantiomeric excess of at least 60% with formaldehyde and hydrocyanic acid, thereby forming an aqueous solution of alanine-bisacetonitrile, (b) saponifying the alanine-bisacetonitrile from step (a) by combining the aqueous solution obtained in step (a) with an aqueous solution of alkali metal hydroxide.

Mixture of L- and D-enantiomers of methyl glycine diacetic acid (MGDA) or its respective mono-, di or trialkali metal or mono-, di- or triammonium salts, said mixture containing predominantly the respective L-isomer with an enantiomeric excess (ee) in the range of from 10 to 75%.

Mixture of L- and D-enantiomers of methyl glycine diacetic acid (MGDA) or its respective mono-, di or trialkali metal or mono-, di- or triammonium salts, said mixture containing predominantly the respective L-isomer with an enantiomeric excess (ee) in the range of from 10 to 75%.

Mixture of L- and D-enantiomers of methyl glycine diacetic acid (MGDA) or its respective mono-, di or trialkali metal or mono-, di- or triammonium salts, said mixture containing predominantly the respective L-isomer with an enantiomeric excess (ee) in the range of from 10 to 75%.

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.