triethyloxonium fluoroborate 、
2-{N'-[3-(2-Methoxycarbonyl-ethyl)-4-methyl-5-[4-methyl-5-oxo-3-vinyl-1,5-dihydro-pyrrol-(2Z)-ylidenemethyl]-pyrrol-(2Z)-ylidene]-hydrazino}-benzoic acid ethyl ester 反应 5.0h,
以50%的产率得到2-[5-[5-Ethoxy-4-methyl-3-vinyl-pyrrol-(2Z)-ylidenemethyl]-3-(2-methoxycarbonyl-ethyl)-4-methyl-1H-pyrrol-2-ylazo]-benzoic acid ethyl ester