“Solvent-less” mechanochemical approach to the synthesis of pyrimidine derivatives

Modified ZnO NPs were synthesized through a sol−gel route with an aromatic capping agent to provide a highly efficient catalyst, NS-5, for the one-pot multicomponent synthesis of various pyrimidine derivatives using a solvent-free ball milling technique. Greenness of the present method was evaluated by calculating an Ecoscale score and E-factor. Characteristics of the method include use of a recyclable catalyst, scale-up to a multigram scale, and ease of product isolation.