Chiral hydantoin resolution
Résumé
A method for resolving chiral hydantoins having general formula (I), wherein R1 is a lower alkyl radical having 1-5 carbon atoms in a linear or branched chain; and R2 is a phenyl radical which is optionally mono-, di- or trisubstituted by lower alkoxy or alkyl radicals or halogen atoms, which are the same or different, or a heteroaryl radical containing a ring of 5-7 links in which the only heteroatom is nitrogen, oxygen or sulphur, or else an aralkyl radical of which the alkyl portion includes one or two carbon atoms and the aryl ring is a phenyl group which is optionally mono-, di- or trisubstituted by lower alkoxy or alkyl radicals or halogen atoms which are the same or different. The hydantoin (I) to be resolved is dissolved in an alcohol or an alkaline solution, a specific proportion of an α-methylbenzylamine enantiomer is added to the solution thereby obtained, and the resulting diastereoisomer salt is isolated and treated with an acid solution to crystallize the hydantoin (I) enatiomer.