3,5-diformyl-4-hydroxybenzoic acid ethyl ester 、
1,4-Dimethylpyridin-1-ium-3-sulfonate 在
哌啶 作用下,
以
乙醇 为溶剂,
反应 0.5h,
以78%的产率得到4-[2-[5-ethoxycarbonyl-2-hydroxy-3-[2-(1-methyl-3-sulfonatopyridin-1-ium-4-yl)ethenyl]phenyl]ethenyl]-1-methylpyridin-1-ium-3-sulfonate