| abstract |
A compound of forumula: <CHEM> wherein R<1> is aryl, or a group of the formula : <CHEM> wherein X is CH or N, and Z is O or N-R<5>, in which R<5> is hydrogen or lower alkyl, R<2> is hydroxy or lower alkoxy, R<3> is hydrogen or lower alkyl which may have suitable substituent(s), R<4> is ar(lower)alkyl which may have suitable substituent(s), A is carbonyl or sulfonyl, and Y is bond or lower alkenylene, and pharmaceutically acceptable salt thereof, processes of their preparation and pharmaceutical compositions comprising them as an active ingredient in admixture with pharmaceutically acceptable carriers. |