A new series of some novel pyrazinamide condensed 1,2,3,4-tetrahydropyrimidines was prepared by reacting of N-(3-oxobutanoyl)pyrazine-2-carboxamide with urea/thiourea and appropriate aldehyde in the presence of catalytic amount of laboratory made p-toluenesulfonic acid as an efficient catalyst. Confirmation of the chemical structure of the synthesized compounds (4a-l) was substantiated by TLC, ...

The mechansim of the three-component Biginelli dihydropyrimidine synthesis was reinvestigated using (1)H and (13)C NMR spectroscopy. Condensation of benzaldehyde, ethyl acetoacetate, and urea (or N-methylurea) in CD(3)OH according to the procedure described by Biginelli produced the expected 6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylates. According to NMR measurements, ther...

Abstract A novel basic ionic liquid based on imidazolium cation is designed, synthesized and successfully used as a catalyst for the one-pot synthesis of 4-Oxo-6-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile derivatives. The remarkable features of this new catalyst are its ethyleneoxy bridge which participates in dissolving organic compound in the ionic liquid and its strong base co...