Direct Additive-free N-formylation and N-acylation of Anilines and Synthesis of Urea Derivatives Using Green, Efficient, and Reusable Deep Eutectic Solvent ([ChCl][ZnCl])

In the current report, we introduce a simple, mild efficient and green protocol for N-formylation and N-acetylation of anilines using formamide, formic acid, and acetic acid as inexpensive, nontoxic, and easily available starting materials just with heating along stirring in [ChCl][ZnCl] as a durable, reusable deep eutectic solvent (DES), which acts as a dual catalyst and solvent system to produce a wide range of formanilides and acetanilides. Also, a variety of unsymmetrical urea derivatives were synthesized by the reaction of phenyl isocyanate with a range of amine compounds using this benign DES in high to excellent yields. [ChCl][ZnCl] showed good recycling and reusability up to four runs without considerable loss of its catalytic activity.