Process for preparing intermediates for thrombin inhibitors

摘要

A process is provided for preparing intermediates of the structure <IMAGE> wherein Rpg is preferably =CHC6H5; and P.G. is a protecting group CBZ or BOC, wherein a protected guanylpyrazole is reacted with an azacycloalkyl, azacycloalkenyl or azaheteroalkyl derivative (such as a piperidine derivative) in the presence of a DBU catalyst. The resulting intermediate may be used as a starting material for preparing thrombin inhibitors.