Der Pharmacia Lettre
Abstract
Author(s): S. K. Pardeshi
Aqueous ethanoic acid is found to be the most favorable medium from various solvent systems used for the oxidative
dehydrogenation of substituted dihydropyridine dicarboxylates to the corresponding pyridine derivatives by using
ceric sulfate tetra hydrate. The reaction is completed within 10 minutes using catalytic amount (0.5 equivalents) of
ceric sulfate and aqueous ethanoic acid at 70 oC temperature with 100% conversion. Ethanoic acid being polar
protic solvent possess dissociable proton due to which acetate ions are formed. These acetate ions facilitate
abstraction of N1 proton. Similarly solubility of ceric sulfate is high (2.021g/lit) in ethanoic acid and due to presence
of strong nucleophile the rate of reaction in ethanoic acid is faster. Ceric sulfate tetra hydrate proves to be superior
catalyst in aqueous ethanoic acid and optimized conditions.
