A series of new N‐alkyl‐2,3,4,9‐tetrahydrofuro[2,3‐b]quinoline‐3,4‐dione and N‐alkyl‐4,9‐dihydrofuro[2,3‐b]‐quinolin‐4‐one derivatives were prepared and evaluated for their anti‐inflammatory activity by the carrageenin hind paw edema method and antiallergic activity by the rat passive cutaneous anaphylaxis method. Among those tested compounds, N‐ethyl‐2,3,4,9‐tetrahydrofuro[2,3‐b]quinoline‐3,4‐dione was the most promising agent which could provide a novel structural prototype for antiallergic agents.