Process for the resolution of enantiomers of 5-heteroaryl-1,3,4-thiadiazinones
AssigneeMerck Patent GmbH
InventorsRochus Jonas, Peter Ersing
Life of this patent
Estimating the term…
Abstract
The invention relates to a process for the resolution of enantiomers of 5-heteroaryl-1,3,4-thiadiazinones of formula I by the kinetic resolution of racemates, characterized in that racemic I is dissolved in an inert solvent or solvent mixture and acylated with a chiral acid chloride. The resulting mixture of diastereoisomers is reacted with an amine or alcohol, thereby achieving a complete resolution of one of the diastereoisomers and a very slight or partial resolution of the other diastereoisomer into the enantiomers on which they are based, the resolution products are then separated off and the remaining pure diastereoisomer is converted to the corresponding pure enantiomer by reaction with an amine or an alcohol.
Claims22
A process for the resolution of enantiomers of 5-heteroaryl-1,3,4-thiadiazinones of formula I:
- ##STR2## wherein R.sup.1 is A,
- R.sup.2 and R.sup.3 are each H or A,
- R.sup.4 is H, A or acyl having 1-15 C atoms,
- A is alkyl having 1-8 C atoms and
- n is 1, 2 or 3,
- by kinetic resolution of a racemate thereof, said process comprising:
- dissolving a racemate of a compound of Formula I in an inert solvent or inert solvent mixture;
- reacting said racemate with a chiral acid chloride;
- reacting the resulting mixture of diastereoisomers with an amine or alcohol, thereby achieving a complete resolution of one of the diastereoisomers and a partial resolution of the other diastereoisomer into the enantiomers on which they are based;
- separating the resolved enantiomer from the unresolved diastereomer;
- converting the unresolved diastereoisomer into its corresponding enantiomer by reaction with an amine or alcohol.
A process according to claim wherein the resulting mixture of diastereoisomers is reacted with an amine.
A process for the resolution of enantiomers of 5-heteroaryl-1,3,4-thiadiazinones of formula I:
- ##STR3## wherein R.sup.1 is A,
- R.sup.2 and R.sup.3 are each independently H or A,
- R.sup.4 is H, A or acyl having 1-15 C atoms,
- A is alkyl having 1-8 C atoms and
- n is 1, 2 or 3,
- by kinetic resolution of racemates thereof, said process comprising:
- dissolving a racemate of compounds of formula I in an inert solvent or inert solvent mixture;
- reacting said racemate with a chiral acid chloride;
- reacting the resultant mixture of diastereoisomers with an amine or alcohol, thereby achieving a complete resolution of one of the diastereoisomers into the enantiomer on which it is based;
- separating the resolved enantiomer from the unresolved diastereoisomer;
- and
- converting the unresolved diastereoisomer into its corresponding enantiomer by reaction with an amine or alcohol.
Dependencies are inferred from the claim text.