Efficient Synthesis of 4-, 5-, and 6-Methyl-2,2‘-bipyridine by a Negishi Cross-Coupling Strategy Followed by High-Yield Conversion to Bromo- and Chloromethyl-2,2‘-bipyridines

Reaction of CBrF2–CBrF2 with hydrazones of aromatic aldehydes

“…Some examples of application of CBrF 2 -CBrF 2 in the nucleophilic substitution have been described [16][17][18][19]. Also this halon was used as bromination agent for organolithium compounds [20,21].…”

New insights into dihydrogenphosphate recognition with dirhenium(i) tricarbonyl complexes bridged by a thiourea moiety

“…46 This was achieved in reasonable yield via the amination of 5-chloromethyl-2,2'-bipyridine 46 rather than the more traditional route through the analogous bromo adduct 47 which has proved to be a severe irritant, and in our experience is not a procedure that can be easily scaled-up to give multigram quantities. Isolation of 5-isothiocyanatomethyl-2,2'-bipyridine was readily achieved following the procedure reported by Wong et al 48 via the tosyl chloride mediated decomposition of a dithiocarbamic acid salt in 61% yield, avoiding the more traditional route via thiophosgene.…”

“…5-Chloromethyl-2,2'-bipyridine 46 was prepared from 2-acetylpyridine via a Kröhnke synthesis to 5-methyl-2,2'-bipyridine, 66 lithiation and subsequent reaction to 5-(trimethylsilyl)methyl-2,2'-bipyridine followed by conversion to the chlorinated derivative by reaction …”

ChemInform Abstract: Practical Aspects of Carbon—Carbon Cross‐Coupling Reactions Using Heteroarenes

“…Subsequent work has revealed the limitations of bipyridine synthesis starting from bromopyridines, and introduced pyridyl triflates as higher-yielding substrates for 2-pyridylzinc chloride. 83 It was demonstrated that commercially available halopyridines are indeed more general substrates for 2-pyridylzinc bromides than previously thought (Table 3). …”