An efficient method for the synthesis of heteroaryl C-O bonds in the absence of added transition metal catalysts

Reaction of 2-chloropyrazine and 2-chloropyrimidine with phenols and alcohols in the presence of K2CO3 in DMSO results in high yielding SNAr coupling. The reaction works particularly well with phenols and yields are comparable or superior to the metal-catalysed couplings described in the literature.