DERIVATION OF FLUORINE-CONTAINING PYRIDINE DICARBOXYLATES .4. N-SUBSTITUTED DIHYDROPYRIDINE DERIVATIVES

The bio‐activity observed for certain Hantzsch derived fluorine‐containing dihydropyridinecarboxylates 6, 11 and 12 and pyridinecarboxylates 10 prompted the preparation of a number of related N‐substituted dihydropyridines for the first time. One method involved a mixed Hantzsch sequence to give 2 from which unexpected side products 3–5 were also isolated and identified. A second preparative method relied on lithiobase deprotonation of 6, 11 and 12 followed by alkylation or acylation to give products 7–9 and 13–15. Structure determination and stereo‐assignments are discussed in terms of their spectral properties, and reaction mode. Copyright © 1990 Journal of Heterocyclic Chemistry