3,6,7,7-tetramethyl-2-oxo-5-(4-sulfobutyl)-3,7-dihydro-2H-oxazolo[5,4-f]indol-5-ium 、 4-[2-[(1E,3E,5E,7E)-8-(N-acetylanilino)octa-1,3,5,7-tetraenyl]-1,1-dimethylbenzo[e]indol-3-ium-3-yl]butane-1-sulfonate 在
sodium acetate 、
乙酸酐 作用下,
以
乙醇 为溶剂,
反应 0.5h,
以75%的产率得到6-{(1E,3E,5E)-7-[1,1-dimethyl-3-(4-sulfobutyl)-1,3-dihydrobenzo[e]indol-(2Z)-ylidene]hepta-1,3,5-trienyl}-3,7,7-trimethyl-2-oxo-5-(4-sulfobutyl)-3,7-dihydro-2H-oxazolo[5,4-f]indol-5-ium sodium salt