CONVERSION OF 2-THIOXO-2,3-DIHYDROQUINAZOLIN-4(1H)-ONES TO N(3)-UNSUBSTITUTED 2-(HET)ARYLQUINAZOLIN-4(3H)-ONES BY COPPER-MEDIATED Pd-CATALYSED CROSS-COUPLING REACTIONS

摘要

With the purpose of searching for new heterocyclic building blocks, a new method to access N(3)-unsubstituted 2-(het)arylquinazolin-4(3H)-ones from 2-thioxo-2,3-dihydroquinazolin-4(1H)-one derivatives was developed. The synthetic protocol was based on the copper-mediated palladium-catalysed cross-coupling reactions of 2-thioxo-2,3-dihydroquinazolin-4(1H)-ones with (het)arylstannanes or their S-benzylated derivatives with (het)arylboronic acids, using CuBr center dot Me2S and CuMeSal as promoters, respectively. A similar transformation was applied for the preparation of 2-aryl[ 1]benzothieno[3,2-d]pyrimidin-4(3H)-ones.