R. Ya. Levina

3-Hydroxyphenyl derivatives of pyrazolines and tetrahydropyridazines in a catalytic decomposition reaction

The isomeric 3-(hydroxyphenyl)-1,4,5,6-tetrahydropyridazines differ from their five-membered-ring analogs, the 3-(hydroxyphenyl)-Δ2-pyrazolines, in their behavior in catalytic-decomposition reactions. The catalytic conversion of 3- (hydroxyphenyl)-1,4,5,6-tetrahydropyridazines takes place at 120–200° C, dehydrogenation being the main reaction. The hydroxyphenylpyrazolines, under the same conditions, undergo decomposition with liberation of nitrogen and formation of the corresponding cyclopropanes.

?-Lactones and ?-lactams: LXV. Synthesis and properties of adducts of 5,6-disubstituted 2-pyridones with dimethyl acetylenedicarboxylate

It has been established that the reaction of 5,6-dialkyl-2-pyridones with dimethyl acetylenedicarboxylate leads to esters of 2-ketopyridin-1-ylfuramic acids, which are readily hydrolyzed in the cold by aqueous solutions of alkalis. The ease of hydrolysis of the esters is apparently explained by intramolecular catalysis as a consequent of the nucleophilic participation of the oxygen of the pyridone ring.