Ultrasound promoted expeditious, catalyst-free and solvent-free approach for the synthesis of N,N′-diarylsubstituted formamidines at room temperature

An effortless and efficient protocol was developed for the synthesis of N,N′-diarylsubstituted formamidines under environment-friendly conditions. Ultrasonic energy was employed to obtain the desired products in excellent yields with high purity under solvent-free and catalyst-free conditions. Products were purified by the crystallization technique to avoid excess utilization of organic solvents.