1H NMR study on the solvent effect on imine-enamine tautomerism of the condensation product of gossypol with 4-aminoantipyrine

According to the 1H NMR data, the condensation product of gossypol with 4-aminoantipyrine in chloroform-d exists in the imine form, while in DMSO-d 6, as the enamine tautomer. The condensation product of 2-hydroxynaphthalene-1-carbaldehyde with 4-aminoantipyrine has the imine tautomer structure in both solvents.