Zahorulko S. Recycling of substituted chromenes under the action of dinucleophiles

The dominant trends in the development of organic chemistry are related to the development of a methodology for structural modification by synthetically promising functional groups to provide a reliable basis for the systematic study of the structure-activity relationship. Therefore, the development of new types of o-hydroxyphenyl derivatives of five, six and seven-membered heterocycles as key objects for further synthetic, structural and biomedical research is a scientifically sound and urgent problem. Earlier, a one-stage method for the synthesis of 4H(2H)-chromen-4-imine (amine) derivatives was developed at the Department of F and TOS of USCUCT. The availability of these compounds has created the conditions for studying their chemical nature to the fullest. It was found that the reaction of 4-amino-2H-(benzo[g])chromen-2-ylidene)malonaldehyde takes place with the disclosure of the pyranyl cycle by the mechanism of 5-exo-trig-cyclization with the formation of previously unknown o-hydroxyphenyl derivatives-2-(1'H,2H-3,4'-dipyrazol-5-yl)phenol(naphthol). The presence of an activated double bond in the chromene ring allows us to consider 4H-chromene-4-imine derivatives as Michael acceptors. The interaction of 4H-chromene-4-imine derivatives with hydrazine hydrate yields the expected substituted (1H-pyrazol-3-yl)-phenols. The structure of the synthesized compounds, which is confirmed by a set of spectral data, suggests that the nature of this interaction is very close to the recycling of deformyl derivatives of 4-amino-2H-chromenes.