A compound having the structurewherein R is an angiotensin receptor blocking groupY is —(CR1R20)1-7R5, or —C(O)(CR1R20)1-7R5；R1 and R20 are independently selected from the group consisting of hydrogen or C1-4 alkyl；R5 is —O—N═N(O)—NR3R4； andR3 and R4 are independently selected from the group consisting of —CH2CH2OH, —CH2CH2OCH3, —C1-4 alkyl, unsubstituted or substituted C1-6 alkenyl, unsubstituted or substituted morpholino, amino, unsubstituted or substituted benzyl, unsubstituted or substituted phenyl, unsubstituted or substituted arylC1-4 alkyl, or R3 and R4 together with the nitrogen atom to which they are attached, form a ring selected from the group consisting ofor a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable salt of the stereoisomer thereof, which is useful for treating hypertension.
