4 piperidinone 2 2 6 6 tetramethyl July 8, 2019 16 32 64 128 4 4 6 6 '- tetramethyl 2 2 '- bipyridine 4 4-bypyridine 4 4'-bipyridine 4 4'-dimethyl-2 2'-bipyridine 2 4 6-trimethylpyridine
