3-Carboxypyridinium Chlorochromate (CPCC): An Inexpensive and Convenient Reagent for Efficient Oxidation of Hantzsch 1,4-dihydropyridines

Tl(NO3)3. 3H2O: A Convenient Oxidising Agent for aromatisation of Hantzsch 1,4-dihydropyridines

An efficient oxidative aromatisation of Hantzsch 1,4-dihydropyridines to the corresponding pyridines by using Tl(NO3)3. 3H2O at ambient temperature is reported. The reactions were fast and the products were isolated in high yields.

A convenient and efficient protocol for oxidative aromatization of Hantzsch 1,4-dihydropyridines using benzyltriphenylphosphonium peroxymonosulfate under almost neutral reaction conditions

Oxidative aromatization of 4-alkyl or aryl and heterocyclic-substituted derivatives of Hantzsch 1,4-dihydropyridines to the corresponding pyridine derivatives has been studied using benzyltriphenylphosphonium peroxymonosulfate as an oxidant in the presence of BiCl(3) under nearly neutral reaction conditions at ambient temperature.

Potassium fluoride/alumina mediated simple synthesis of Hantzsch 1, 4-dihydropyridines

A general and practical technique to achieve synthesis of 1,4-dihydropyridines in excellent yields has been investigated using potassium fluoride/alumina (KF/Al2O3) as a solid base. The ammonia was obtained either from thermal decomposition of ammonium acetate or by passing ammonia gases in the form of bubbled through hetereogenous reaction medium using an apparatus.