Antihypertensive dihydropyridines with 1,4,4-trisubstitution

Dihydropyridines with 1,4,4-trisubstitution were synthesized and tested for antihypertensive activity in a spontaneously hypertensive rat model. This substitution pattern on the dihydropyridine nucleus differs markedly from that found most active in the structure-activity relationship established for nifedipine-like compounds. However, some were found to significantly lower blood pressure at testing doses (30 mg/kg, ip and 100 mg/kg, po) for up to 24 h. Methyl 1,4-dihydro-4,4-dimethyl-1-pyridinepropanoate (2-1), for example, lowered blood pressure 71 mmHg at 30 mg/kg, ip and the effect endured for greater than 24 h. Unlike prototypical dihydropyridines such as nifedipine, these compounds did not seem to have any effect on calcium channels.