One-pot and solvent-free synthesis of diethyl 4-hydroxy-6-nitro-4H-chromene-2,3-dicarboxylate (DHNC).

Structure elucidation of DHNC using UV–vis, FT-IR, ¹H and ¹³CNMR and mass spectra.

Quantum chemical calculations using B3LYP/6–311++G(d,p) and PBE1PBE/6–311++G(d,p) methods.

Good agreement between the theoretical results and experimental observations.