Novel 2-amino-1,4-dihydropyridine calcium antagonists. I. Synthesis and antihypertensive effects of 2-amino-1,4-dihydropyridine derivatives having nitroxy-alkoxycarbonyl groups at 3- and/or 5-position.

Novel 2-amino-1,4-dihydropyridine derivatives, which contain nitroxy-alkoxycarbonyl groups at the 3- and/or 5-position, were synthesized and their pharmaceutical effect was evaluated in spontaneously hypertensive rats. The structure-activity relationships are discussed in terms of potency, onset-rapidity, and duration of antihypertensive activity. Remarkably prolonged duration of antihypertensive action was observed when a tertiary amino group was introduced on either side of an ester chain.