Dihydropyrimidines are described as potent mimics of dihydropyridine calcium channel blockers. They are regarded as aza-analog of nifedipine related dihydropyridines. Tetrahydropyrimidines were prepared under microwave irradiations and were converted to S-alkyl-1,4-dihydropyrimidines. All synthesized compounds were characterized on basis of their spectral data. Synthesized compounds were tested on rat uterus and rabbit heart. These compounds show smooth muscle relaxing property on rat uterus and increase in coronary flow and amplitude of rabbit heart. These can be used in conditions like congestive heart failure unlike nifedipine which cannot be useful in such conditions.