Abstract: A compound of formula (I), wherein R.sup.1 and R.sup.2 are independently selected from chloro, fluoro, bromo, C.sub.1-6 alkyl, C.sub.1-6 alkoxy or C.sub.1-6 haloalkyl provided that both R.sup.1 and R.sup.2 are not fluoro; R.sup.3 and R.sup.4 are independently selected from hydrogen and C.sub.1-6 alkyl, and pharmaceutically acceptable salts, solvates or physiologically functional derivatives thereof, their use in medicine, particularly the phrophylaxis or treatment of conditions associated with inflammation, arthritis, or pain, pharmaceutical compositions comprising them, and processes for their preparation are disclosed.