摘要:
A process for preparing compounds represented by general formulae (5) and (6) in the following reaction scheme or salts thereof, wherein R1 represents a nitrogen protective group; R2 represents a methanesulfonyl or p-toluenesulfonyl group; R3 represents a hydrogen atom, an aralkyl group, or an alkyl group having 1 to 6 carbon atoms, and X represents a halogen atom. The above process is useful as a commercial process for preparing intermediates of anticoagulant aromatic amidine derivatives described in Japanese Patent Laid-Open No. 208946/1993.