| abstract |
A compound of the formula:-n or a pharmaceutically acceptable salt thereof, nwherein R¹ is -OR² or -NH₂ n in which R² is H, C₁-C₆ alkyl, phenyl or benzyl, the phenyl and benzyl groups being optionally substituted on the aromatic ring by one or two substituents each selected from C₁-C₄ alkyl, C₁-C₄ alkoxy and halo. n The compounds are useful in the treatment of hypertension, angina, renal impairment and acute renal failure. |