Process for the preparation of enantiomerically pure 1-substituted-3-aminoalcohols

Abstract

A process for the preparation of N-monosubstituted β-aminoalcohol sulfonates of formula (Ia), (Ib): wherein Ris C-aryl or C-heteroaryl, each optionally being substituted with one or more halogen atoms and/or one or more C-alkyl or C-alkoxy groups, Ris C-alkyl or C-aryl, each aryl optionally being substituted with one or more halogen atoms and/or one or more C-alkyl or C-alkoxy groups and wherein Ris selected from the group consisting of C-alkyl, C-cycloalkyl, C-aryl and C-aralkyl residues. The process has the steps of (a) reacting a methyl ketone, a primary amine, formaldehyde and a sulfonic acid, at a pressure above 1.5 bar, optionally in a organic solvent, the organic solvent optionally containing water, to afford N-monosubstituted β-aminoketone sulfonates of formula (II): wherein R, Rand Rare as defined above, and (b) asymmetrically hydrogenating. The sulfonates in the presence of a base and a catalyst of a transition metal and a disphosphine ligand, in a polar solvent, optionally in the presence of water.