A novel Deep Eutectic Solvent (ChCl/THFTCA-DES) was prepared by a mixture (2:1) of choline chloride [(CH3)3N+CH2CH2OH]Clˉ = (ChCl) and tetrahydrofuran-2,3,4,5-tetracarboxylic acid (THFTCA) as a cheap, simple, and non-toxic method, characterized by FT-IR, densito-meter, eutectic point, and 1 H NMR techniques and used as a capable and new catalyst for the synthesis of ten Henna-based benzopyranophenazine‑carbonitriles.
