5-Acyl-l, 2-dihydro-3H-pyrrolo [1, 2-a] pyrrole-l-carboxylic acids and the homologous pyridine and azepine derivatives were synthesized and assayed for antiinflammatory and analgesic activity. 5-Benzoyl-l, 2-dihydro-3H-pyrrolo-[1, 2-a] pyrrole-l-carboxylic acid (62) and the corresponding p-methoxy compound 74 were selected for evaluation as analgesic agents in humans on the basis of their high potency in the mouse phenylquinone writhing ...