A concise one-pot synthesis of highly functionalized pyridines has been developed. The first step in the reaction sequence is the formal insertion of rhodium vinylcarbenoids across the N-O bond of isoxazoles. Upon heating, the insertion products undergo a rearrangement to give 1,4-dihydropyridines. DDQ oxidation then affords the corresponding pyridines in 31-84% yield. The process has proven ge...

Recent studies showed that 1,4-dihydropyridine-3,5-dicarbamoyl derivatives with lipophilic groups have significant antitubercular activity. In this study, we have synthesized new derivatives of 1,4-dihydropyridines bearing carbmethoxy and carbethoxy group at C-3 and C-5 of the 1,4-dihydropyridine ring. In addition, 1H-pyrazole ring is substituted at C-4 position. These analogues were synthesize...

Calcium antagonists comprise 2 main subclasses, dihydropyridines and nondihydropyridines, and have been studied extensively in hypertensive patients. Early meta-analyses suggested that short-acting calcium antagonists were associated with higher mortality rates resulting from cardiovascular events and other etiologies. Recent meta-analyses failed to show any substantive difference between long ...

In the setting of soaring popularity, postmarketing studies of calcium channel blockers came to suggest an increase in a variety of major adverse end points. The evidence, however, was largely observational, and large-scale trials capable of addressing the concerns were wanting. Clinical trials now support the safety and efficacy of the long-acting dihydropyridines for patients with both uncomp...

The solvent-free preparation of unsymmetrical N-aryl-5,6-unsubstituted-1,4-dihydropyridines (DHPs) by ball-milling was investigated. Three different mechanochemical domino reactions (one-pot/one step or stepwise) were studied, the process parameters underlying any modulated and differences with solution-based mechanistic pathways disclosed. selection most suitable method driven physical state b...

BACKGROUND Dialkyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylates (1,4-DHP) have now been recognized as vital drugs. Some of these derivatives such as amlodipine, felodipine, isradipine, etc. have been commercialized. In view of wide range of biological properties associated with 1,4-DHP and owing to the biological importance of the oxidation step of 1,4-DHP, we carried out the synthesis a...