dimethyl 2-(6-methoxy-11,11-dimethyl-2,3-dioxo-10-sulfanylidene-1-azatricyclo[6.3.1.04,12]dodeca-4,6,8(12)-trien-9-ylidene)-1,3-dithiole-4,5-dicarboxylate 、
丁炔二酸二甲酯 以
甲苯 为溶剂,
以68%的产率得到tetramethyl 2'-methoxy-7',7'-dimethyl-4',5'-dioxo-4',5'-dihydro-7'H-spiro[1,3-dithiole-2,11'-pyrrolo[3,2,1-ij]thiopyrano[2,3-c]quinoline]-4,5,9',10'-tetracarboxylate