“…The 4,4’‐dinitro and 4,4’‐dibrom‐2,2’‐bipyridine‐6,6’‐dicarboxylic acids 2 were prepared by the oxidation of corresponding 4,4’‐substituted 6,6’‐dimethyl‐2,2’‐bipyridines which were synthesized according to the following scheme (Scheme ). Chromium oxide oxidation were previously used for 2,2‐bipyridine‐6,6’‐dicarboxylic acid preparation ,. Bis‐N‐oxide of 6,6’‐dimethyl‐2,2’‐bipyridine was nitrated to provide 4,4’‐dinitro‐6,6’‐dimethyl‐2,2’‐bipyridine; after that the 4,4’‐dibromo‐6,6’‐dimethyl‐2,2’‐bipyridine was prepared in high yield by a method modified from the original work of Mukkala and Kankare .…”