| 摘要 |
A compound of the formula : <CHEM> wherein R<1> is ar(lower)alkyl which may have suitable substituent(s), R<2> is hydrogen, lower alkyl which may have suitable substituent(s), or a group of the formula : <CHEM> (in which A is lower alkylene and X is halogen), n is 0, 1 or 2 and Y is -CH2-CH2- or <CHEM> and a pharmaceutically acceptable salt thereof, processes for their preparation and pharmaceutical compositions comprising them as an active ingredient in admixture with pharmaceutically acceptable carriers. |
