Various dimethyl 3-substituted pyrrole-2, 4-dicarboxylates (3) were synthesized by the reaction of methyl isocyanoacetate (2) with methyl α-isocyanoacrylates (5) in the presence of base. This type of reaction was also applicable to the preparation of 3-substituted pyrrole-2, 4-dicarboxamides (10) by employing appropriate amide compounds (8) or (9) and (12) as reactants. Hydrolysis followed by decarboxylation of the pyrrole diester compounds (3) gave 3-substituted pyrroles (14) in good yields. A series of these compounds (14) showed antiinflammatory activities against carrageenan-induced rat paw edema. Among the compounds tested, 3-(2-chlorophenyl) pyrrole (14d) was found to be more potent than mefenamic acid.