Compounds belonging to the 5-acyl-3,4-dihydropyrimidine-2-thione family were obtained using a solvent-free Biginelli condensation with or without the use of a catalyst. An unprecedented solid-phase procedure involving a polymer-supported aldehyde allowed the preparation of a series of 5-aroyl derivatives starting with crude diketones obtained from their corresponding aryl esters.
Microwave-Assisted Synthesis of Some Pyrimidine Derivatives
作者:A. Mobinikhaledi、N. Forughifar
DOI:10.1080/10426500600862977
日期:2006.11.1
Oxo-and thioxopyrimidines 4a–i were synthesized using the Biginelli three-component cyclocondensation reaction of an appropriate β-diketone, arylaldehyde, and (thio)urea under microwave irradiation. Yields of products following recrystallization from ethanol were of the order of 65–90%. 1H and 13C NMR spectroscopy and elemental analysis were used for structural assignment.
We reported the use of Brønsted acid methane sulfonic acid as a promoter for three component Biginelli cyclocondensation reaction of aryl aldehydes, acetylacetone and thiourea at 120 °C to afford the corresponding to 1,2,3,4-tetrahydropyrimidin-2(1H)-thiones in good to excellent yields in short span of time. Reaction is efficient, facile and rapid. The structural elucidation of products was done by NMR, IR and elemental analysis.