4-ethoxycarbonylmethyl-1-(3-propylsulfonato)-pyridinium betaine 、
6-[ethyl-(4-formyl-3-hydroxy-phenyl)-amino]hexanoic acid 在
哌啶 作用下,
以
甲醇 为溶剂,
反应 10.0h,
以21%的产率得到4-{7-[(5-carboxy-pentyl)-ethyl-amino]-2-oxo-2H-chromen-3-yl}-1-(3-propylsulfonato)-pyridinium betaine