Metal- and Solvent-Free Synthesis of Substituted Pyrimidines via an NH₄I‑Promoted Three-Component Tandem Reaction

A facile and practical approach for the preparation of substituted pyrimidines from ketones, NH₄OAc, and N,N-dimethylformamide dimethyl acetal has been described. This NH₄I-promoted three-component tandem reaction affords a broad range of substituted pyrimidines in acceptable yields under metal- and solvent-free conditions. The present methodology features the advantages of simple and easily available starting materials, metal- and solvent-free conditions, a broad substrate scope with good functional group tolerance, and gram-scale synthesis.