A new non-steroidal anti-inflammatory analgesic: gamma-oxo (1,1'-biphenyl)-4-butanoic acid (fenbufen). Chemistry and activity of analogs.

100 analogs of gamma-oxo(1,1'-biphenyl)-4-butanoic acid (fenbufen) were prepared and tested using the carrageenin, polyarthritis, and UV erythema anti-inflammatory tests and the 2-phenyl-1,4-benzoquinone writhing and inflamed paw pressure analgesic tests. Only three retained the same full spectrum of activity as fenbufen: dl-4-(4-biphenyly)-4-hydroxybutyric acid, dl-4-(4-biphenylyl)-1,4-butanediol, and 4-biphenylacetic acid. Fenbufen had the same spectrum of activity as acetylsalicylic acid (ASA), phenylbutazone, and indometacin in the five tests. In addition, dose-response derived potencies show fenbufen more potent than ASA and at least as potent as phenylbutazone in all five tests.