One-pot synthesis of 2-oxo-1,2,3,4-tetrahydropyrimidines using homogeneous catalyst under solvent-free conditions

Synthesis of 2-oxo-1,2,3,4-tetrahydropyrimidine derivative was reported via P. Biginelli three-component condensation reaction. This work reports on the preparation of 2-oxo-1,2,3,4-tetrahydropyrimidines using the NaF as catalyst. One-pot condensation reactions were carried out for various aryl aldehydes, ethyl acetoacetate, acetyl acetone and urea under solvent-free conditions at 100 °C and afforded the target molecules in good to excellent yields. Furthermore, this reaction was examined in various solvents such as EtOH, CH3CN, H2O andis DMSO. Compared with classical Biginelli reaction conditions, this method has the advantage of high yields of product and shorter reaction times. Since this catalyst is very soluble in the water, however separation of this catalyst is very comfortable. At the same conditions, the time three-component condensation reaction for acetylacetone reactant is shorter then ethyl acetoacetate reactant and the yields of two groups are close together. However, according to the experimental data, we have proposed the suitable mechanism for this reaction.