| abstract |
The present invention describes a method for the synthesis of enantiomerically pure 3-amidinophenylalanine derivatives, which are used as pharmaceutically effective urokinase inhibitors, by starting from 3-cyanophenylalanine derivatives. The methods of manufacture comprising only one synthesis step lead to new intermediates, namely 3-hydroxyamidino- and 3-amidrazonophenylalanine derivatives. These intermediates or their acetyl derivatives can be reduced into the desired 3-amidinophenylalanine derivatives under gentle conditions (H 2 or ammonium formiate, Pd/C (approx. 10%), ethanol/water, room temperature, normal pressure or also H 2 , Pd/C, AcOH or HCl/ethanol, 1-3 bar) in excellent yields and in an enantiomeric excess of up to 99.9%. |