A new regioselective synthesis of 5- and 6-aryluracil bases based on direct C–H arylations of diverse 1,3-protected uracils has been developed. Benzyl-protected uracils were selected as the most practical in terms of stability during the arylation and facile cleavage of the benzyl groups. Pd-catalyzed C–H arylations in the absence of CuI gave preferentially 5-aryl-, whereas the reactions in the presence