Various 2'-phenoxymethanesulfonanilide derivatives were synthesized and evaluated for antiinflammatory and analgesic activities. Some compounds bearing an electron-attracting substituent at the 4'-position strongly inhibited adjuvant-induced arthritis in rats and acetic acid-induced writhing syndrome in mice without causing gastro-intestinal irritation. Among them, 4'-cyano-(FK867) and 4'-acetyl-(FK3311) 2'-(2,4-difluorophenoxy)methanesulfonanilides were selected as the candidates for further development.