5-bromo-3-methyl-pyrrole-2,4-dicarboxylic acid 4-ethyl ester

diethyl 5-bromo-3-methyl-1H-pyrrole-2,4-dicarboxylate

3-ethoxycarbonyl-4-methyl-1H-pyrrole-2,5-dicarboxylic acid

3,5-二(乙氧羰基)-4-甲基-1H-吡咯-2-羧酸

3-甲基-1H-吡咯-2,4-二羧酸二乙酯