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