The series of 4-(2',4'-difluorobiphenylyl)-2-methylbutyric acid (deoxoflobufen, 1) and its four amides and two salts were prepared and tested for anti-inflammatory activity in rats and mice, using as models carrageenan-induced paw oedema, pleuritis, and arachidonic acid-induced ear inflammation, and on leucotriene B 4 production in cells.