Synthesis and antihypertensive activity of 1,4-dihydropyridine derivatives with a 4-(disubstituted phenyl) ring and an aminoalkyl ester group: highly potent and long-lasting calcium antagonists

1,4-Dihydropyridine: synthetic advances, medicinal and insecticidal properties

1,4-Dihydropyridine (1,4-DHP) is one of the foremost notable organic scaffolds with diverse pharmaceutical applications. This study will highlight recent accomplishments in the construction of 1,4-DHP with structural and functional modifications using multi-component one-pot and green synthetic methodologies. The various intrinsic therapeutic applications, ranging from calcium channel blocker, anti-oxidative, anticancer, anti-inflammatory, anti-microbial, anti-hypertensive, anti-diabetic, anticoagulants, anti-cholinesterase, neuro-protective, and other miscellaneous activities, have been summarized with a focus on their structure-activity relationship (SAR) investigations. In addition, the insecticidal properties have been collated and discussed. Researchers in the fields of medicinal chemistry and drug development will find the summarized conclusions of this study incredibly informative, instructional, and valuable.

Rapid synthesis and biological evaluation of 1,4-dihydropyridine derivatives containing a benzothiazolyl moiety

A series of N-(6-methylbenzothiazolyl)-2,3,5,6-tetrasubstituted-4-(aryl)-1,4-dihydropyridines were synthesized by reaction of 2-amino-6-methylbenzothiazole, aromatic aldehyde and active methylene compound in methanol by conventional, as well as, microwave irradiation (solvent free and solid support) methods. The microwave irradiation technique gives better yield and shorter reaction time. Among solid supported microwave irradiation better yields are obtained in acidic alumina as compared to silica, neutral alumina, and basic alumina. All compounds were tested for antibacterial and antifungal activities and results have been compared with standard drugs. Entomological activities were also tested. The results showed that a change in the substitution pattern in 1,4-dihydropyridine derivatives may cause a marked effect on their antimicrobial activity.

The new generation dihydropyridine type calcium blockers, bearing 4-phenyl oxypropanolamine, display alpha-/beta-adrenoceptor antagonist and long-acting antihypertensive activities

A new series of dihydropyridine derivatives, bearing oxypropanolamine moiety on phenyl ring at the 4-position of the dihydropyridine base, were prepared. Oxypropanolamine was synthesized by replacing the phenolic OH of vanillin or other compounds, having a phenyl aldehyde group, with epichlorohydrin, followed by cleavaging the obtained epoxide compounds with tert-butylamine, n-butylamine or 2-methoxy-1-oxyethylamino benzene (guaiacoxyethylamine), respectively. Obtained various oxypropanolamine compounds, still remaining a phenyl aldehyde moiety, were then performed by Hantzsch condensation reaction with methylacetoacetate or ethylacetoacetate, respectively, to give our new series of dihydropyridine linked with the 4-phenyl ring. These compounds were evaluated for inotropic, chronotropic, and aorta contractility that associated with calcium channel and adrenoceptor antagonist activities. Dihydropyridine derivatives that with oxypropanolamine side chain on their 4-phenyl ring associated alpha-/beta-adrenoceptor blocking activities created a new family of calcium entry and the third generation beta-adrenoceptor blockers. Optimizing this research to obtain more potent alpha-/beta-adrenoceptor blocking and long-acting antihypertensive oxypropanolamine on the 4-phenyl ring of dihydropyridine series compounds was thus accomplished and classified as third generation dihydropyridine type calcium channel blockers, in comparison with previous short-acting type nifedipine and long-acting type amlodipine. We concluded that compounds 1a, 1b and 1g showed not only markedly high calcium-antagonistic activity but also the highest antihypertensive effect; compounds 1b, 1c, 1f, 1g, 1i and 1j induced sustained antihypertensive effects are major and attributed to their calcium entry and alpha-adrenoceptor blocking activities in the blood vessel due to their introduction of 2-methoxy, 1-oxyethylamino benzene moiety in the side chain on the 4-phenyl ring of dihydropyridine. Bradycardiac effects of all the compounds 1a-1j resulted from calcium entry and beta-adrenoceptor blocking, which attenuate the sympathetic activation-associated reflex tachycardia in the heart. We selected compound 1b as candidate compound for further pharmacological and pre-clinical evaluation studies.