| abstract |
8-phenylxanthine derivatives of formula (I), wherein R?1, R2 and R3¿ each independently represent a hydrogen atom or an alkenyl, alkynyl, cycloalkyl or alkylcarbamoyl group or an alkyl group which may be unsubstituted or substituted, or a benzyl or phenyl group which may be unsubstituted or substituted either R?4 and R5¿ together with the nitrogen atom to which they are attached form a 3 to 7-membered ring comprising a total of from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulphur, which ring may be unsubstituted or substituted, or R4 is as defined for R?1 and R5¿ represents an alkenyl, alkynyl, cycloalkyl, mono-or di-alkylamino, alkylcarbamoyl, aminocarboiminoyl group or a substituted alkyl group or R5 represents a group of formula -(CH¿2)n-R?7 wherein n is an integer from 0 to 4 and R7 represents a 3 to 7-membered ring comprising from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulphur, which ring may be unsubstituted or substituted, R6 represents a hydrogen atom or an alkyl group; and the -SO¿2NR?4R5 group is in the 4 or 5 position on the phenyl group; and pharmaceutically acceptable salts thereof, processes for their production, pharmaceutical compositions containing them and their use as phosphodiesterase 5 inhibitors. |