I. Goba

15N NMR of 1,4-dihydropyridine derivatives.

In this article, we describe the characteristic 15N and 1HN NMR chemical shifts and 1J(15N–1H) coupling constants of various symmetrically and unsymmetrically substituted 1,4‐dihydropyridine derivatives. The NMR chemical shifts and coupling constants are discussed in terms of their relationship to structural features such as character and position of the substituent in heterocycle, N‐alkyl substitution, nitrogen lone pair delocalization within the conjugated system, and steric effects. Copyright

Synthesis of Novel Unsymmetrically Substituted 1,4-Dihydroisonicotinic Acid and its Derivatives

The synthesis of new unsymmetrically substituted 1,4-dihydroisonicotinic acid bearing cyano and acetyl groups in positions 3 and 5 of the heterocycle has been developed. The methyl, ethoxycarbonylmethyl, and propionyloxymethyl esters of the acid have been obtained. The method of N-alkylation reaction of synthesized 1,4-dihydroisonicotinic acid esters has been elaborated.

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

Summary Stable heterocyclic hydroperoxide can be easily prepared as a product of fast oxidation of a 1,2,3,4-tetrahydropyridine by 3O2 if the solution is exposed to sunlight. The driving force for the photoinduced electron transfer is calculated from electrochemical and spectroscopic data. The outcome of the reaction depends on the light intensity and the concentration of O2. In the solid state the heterocyclic hydroperoxide is stable; in solution it is involved in further reactions.