One-Pot Two-Step Solvent-Free Rapid and Clean Synthesis of 2-(Substituted Amino)pyrimidines by Microwave Irradiation

A series of diversely 2-(substituted amino)pyrimidines (along with ring substitution) has been synthesized under solvent- and catalyst-free microwave conditions from substituted guanidines and β-diketones. The substituted guanidines are synthesized from (S)-methylisothiourea sulfate and different amines (various alkyl, aryl, or heterocyclic and also chiral amines) under microwave irradiation. These two-step reactions are performed in one-pot without isolating any intermediate. This protocol has been successfully applied for the synthesis of bisaminopyrimidines and 2-substituted aminopyrimidines containing chiral moiety where chirality remains undisturbed.