N-Methyl and Nn-butyl-2-(2-boronophenyl) benzimidazoles are accessed from the corresponding mono-N-alkyl-ortho-phenylenediamines, either using a polyphosphoric acid- mediated cyclisation with ortho-bromobenzoic acid, or preferably using an Oxone™- mediated cyclisation of the corresponding aldehyde, followed by a lithium-exchange and borylation sequence. The resulting boronic acids show unusual physical and chemical ...