Synthesis and analgetic-antiinflammatory activity of 3,5-pyrazolidinediones bearing small-ring cycloalkyl groups.

: Six 1,2-diphenyl-3,5-pyrazolidinediones substituted in the 4-position with small-ring cycloalkyl groups were prepared and tested for analgetic-antiinflammatory activity. Three of the synthesized compounds exerted an analgetic-antiinflammatory activity quantitatively superior to that of phenylbutazone used as a reference standard. In particular, one of the compounds (VI) proved twice as potent as phenylbutazone while possessing the same ulcerogenic effect.