A modified approach for the site-selective direct C-6 arylation of benzylated uracil

An efficient methodology is reported for the regioselective C-6 arylation of protected uracil via the palladium catalyzed C-H functionalization of 1-(4-methoxybenzyl)-3-methylpyrimidine-2,4(1H,3H)-dione with (hetero)aryl halides and boronic acids. Utilization of the Pd(OAc)(2)/Xantphos catalytic system with a stoichiometric amount of Cul and DBU as the base was vital for the success of this protocol. The methodology is facile and compatible with aryl bromides, iodides and boronic acids and hence affords broad substrate scope and diversity. (C) 2019 Elsevier Ltd. All rights reserved.