Solvent-free and one-pot Biginelli synthesis of 3,4-dihydropyrimidin-2(1H)-ones and 3,4-dihydropyrimidin-2(1H)-thiones using ionic liquid N,N-diethyl-N-sulfoethanammoniumchloride {[Et3N–SO3H]Cl} as a green catalyst

In this work, the ionic liquid triethylamine-bonded sulfonic acid {[Et3N–SO3H]Cl}, N,N-diethyl- N-sulfoethanammonium chloride was used as a green acidic homogeneous catalyst in order to synthesis 3,4-dihydropyrimidin-2(1H)-ones and 3,4-dihydropyrimidin-2(1H)-thionesas two categories of heterocycles. The dihidropyrimidineones and dihydropyrimidinethiones derivatives which were synthesized in this method can be regarded as two important categories of heterocyclic compounds with biologic and pharmacologic activity. The ionic liquid that was used in these reactions acts as Bronsted acid and green homogeneous catalyst. It has N-S bond in its cationic fragment and can be easily synthesised. The advantages of our method are as follow: solvent-free conditions, green process and high isolated yield of products.