Reaction of Cuprate Reagents with Pyridine in the Presence of Chloroformate. A Novel Synthesis of 1,4-Dihydropyridine Derivatives

Abstract

Reaction, under appropriate conditions, of lithium dialkyl- or diarylcuprates with pyridine in the presence of methyl chloroformate afforded, in good yields, 1-carbomethoxy-4-alkyl (or aryl)-1,4-dihydropyridines. Also formed, in limited but varying amounts (∼2–11%), were the corresponding 1,2-dihydropyridine derivatives.