NMR spectra

In this work, the interaction of diarylmethylidene piperidones with acetylacetone and acetoacetic ester has been studied. It has been shown that the transition to piperidone in the basis of dienone does not allow the selective synthesis of products. It has been found that the direction of the reaction with 1,3-C,C-dinucleophilic reagents is infl uenced by the nature of peripheral ylidene substituents, which allows targeted synthesis of O-heterocyclization products (hexahydropyranopyridines) by introducing an NO2 group into the arylmethylidene fragment.

In the three-component condensation of thiophenecarbaldehyde, cyclohexanone and 3-amino-1,2,4-triazole triazolohexahydroquinazolines are formed, which are isomeric in the type of the ring junction and the double bond position in them, the structure of which is established by 1H NMR spectra. With the GC-EIMS-analysis of the composition of the reaction mass at various temperatures, it has been established that an intermediate in the formation of final products is azomethine (instead of a possible ?,?-unsaturated ketone).

Aryl-substituted triazolohexahydroquinazolines have been synthesized by means of three-component condensation of pnitro(pbromo) benzaldehydes, cyclohexanone, 1,2,4-triazol-3-amine. A scheme of the reaction mechanism is proposed, which makes it possible to explain the features of the behavior of p-nitro(bromo) benzaldehydes in condensation reactions in comparison with their ortho-substituted analogs.