4-(乙氧基羰基甲氧基)苯甲醛 、
2-ethyl-7-(4-ethyl-3,5-dimethyl-1H-pyrrol-2-yl)-5,5-difluoro-1,3-dimethyl-5H-5l4-pyrrolo[1',2':3,4][1,3,2]diazaborinino[6,1-a]isoindol-6-ium 以30%的产率得到3-(4-(2-ethoxy-2-oxoethoxy)styryl)-2-ethyl-7-(4-ethyl-3,5-dimethyl-1H-pyrrol-2-yl)-5,5-difluoro-1,12-dimethyl-5H-5l4-pyrrolo[1',2':3,4][1,3,2]diazaborinino[6,1-a]isoindol-6-ium