8-PHENYLXANTHINE DERIVATIVES AND THEIR USE AS PHOSPHODIESTERASE INHIBITORS

摘要

8-phenylxanthine derivatives of formula (I), wherein R<1>, R<2> and R<3> 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 R<5> 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 R<4> is as defined for R<1> and R<5> represents an alkenyl, alkynyl, cycloalkyl, mono-or di-alkylamino, alkylcarbamoyl, aminocarboiminoyl group or a substituted alkyl group or R<5> represents a group of formula -(CH2)n-R<7> wherein n is an integer from 0 to 4 and R<7> 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, R<6> represents a hydrogen atom or an alkyl group; and the -SO2NR<4>R<5> 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.