ethyl 1,4-dimethyl-5H-pyrido(4,3-b)indole-3-carboxylate

phenyl 3-(1-(phenylsulfonyl)-1H-indol-2-yl)but-2-enoate

5-[[2-[1-(benzenesulfonyl)indolyl]]ethylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione

3-(2-indolyl)-2-butenoic acid

methyl 3-(2-indolyl)-2-butenoate