| 摘要 |
There are disclosed compounds having the formula <IMAGE> wherein R1 is hydrogen, loweralkyl, arylloweralkyl, aryl or heteroaryl; R2 is hydrogen or loweralkyl; R3 is loweralkyl, loweralkoxyloweralkyl, cycloalkyl, arylloweralkyl or heteroarylmethyl; and R4 is hydrogen or loweralkyl; or a pharmaceutically acceptable acid addition salt thereof, which are useful for alleviating pain and lowering blood pressure, methods for synthesizing them, and pharmaceutical compositions comprising an effective amount of such a compound. |
