Process for the separation of enantiomers of 3,6-dihydro-1,3,5-triazine derivatives

A method for the chromatographic separation of the enantiomers of a compound of the formula I or an acid-addition salt thereof, wherein said separation of the enantiomers is carried out on a chiral ion exchanger material

• wherein
• R1 and R2 are A;
• R3 and R4 are H;
• R5 is H,
• R6 is A,
• A is unbranched or branched alkyl having 1-10 C atoms, wherein 1-7 H atoms may be replaced by F, or cyclic alkyl having 3-7 C atoms;
• and
• comprising separating the enantiomers on a chiral ion exchanger which is
• a) of the structure below wherein X is a counterion determined by the type of buffer salt in the mobile phase and the sphere represents a support,
• b) of the structure below where the sphere represents a support:
• or
• c) contains one of the following structures, a spacer and a support,