| 摘要 |
Compounds useful in the prevention and/or treatment of hypertension, congestive heart failure, arrhythmia, migraine, vasospastic disorders, and asthma are represented by the formula <IMAGE> (I) wherein: R, R1, R2, R3, and R4 are independently hydrogen or lower alkyl of one to four carbon atoms; and R5 and R6 are independently hydrogen, lower alkyl of one to four carbon atoms or lower alkoxy of one to four carbon atoms; and the pharmaceutically acceptable acid addition salts thereof. |
