diethyl 3-phenyl-1H-pyrrole-2,4-dicarboxylate

diethyl 3-isocyano-2,2-dimethylbutanedioate

ethyl 5-bromo-3-methyl-1H-indole-2-carboxylate

Ethyl 5-tert-butyl-1,3-oxazole-4-carboxylate

ethyl 3-(dimethylamino)-2-isocyanoprop-2-enoate