Recyclization of 3-substituted-6,8-dimethylchromones with some heterocyclic enamines: Spectroscopic, quantum calculations (HOMO–LUMO, MEP, NLO), biological evaluation, and ADME investigation

The chemical reactivity of some 6,8-dimethylchromones was studied toward certain heterocyclic enamines. Treatment of carboxaldehyde 1a with the certain enamines proceeded via condensation with concomitant γ-pyrone ring opening. Reaction of carbonitrile 1b with enamine derivatives proceeded through opening of γ-pyrone moiety associated with cycloaddition into the nitrile function. A novel angular chromenopyrazolopyridine and chromenopyridopyrimidines were efficiently synthesized from reacting carboxamide 1c with the current enamines. Moreover, frontier molecular orbitals analysis, electronegativity, global hardness, global softness, ionization energy, and HOMO-LUMO energy gap were calculated by using DFT/B3LYP/6-311++G(d,p) level. Using the GIAO approach, the ¹H and ¹³C NMR spectra were calculated and showed good agreement with the experimental values. Additionally, the nonlinear optical (NLO) properties of the prepared compounds were found higher than urea. MEP was utilized to ascertain reactive sites within the molecules. The produced compounds exhibited varying degrees of inhibitory effect when tested for their antimicrobial and anticancer properties. The evaluation of ADME (absorption, distribution, metabolism, and excretion) parameters indicated good drug-like properties of all the investigated compounds.