Straightforward and efficient synthesis of 3-benzyloxy-4-bromopicolinate ester and 3-benzyloxy-5-bromopicolinate ester, common building blocks for pharmaceuticals and agrochemicals

A practical and rapid preparation of 3-benzyloxy-4-bromo and 3-benzyloxy-5-bromopicolinate esters 10 and 16 was developed in four steps, respectively, in 38% and 31% overall yield. Then their viability as partners for cross-coupling reactions has been evaluated in Suzuki-Miyaura, Hartwig-Buchwald, and Sonogashira reactions to synthesize biologically relevant targets. The preparation of these two highly functionalizable pyridines 10 and 16 has been never described to date in the literature and could be used as common building block for the preparation of several biologically active compounds or agrochemical products.