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[摘要]：An efficient method for prepn. of 2,4-dibromopyridine and 4,4'-dibromo-2,2'-bipyridine from 2-bromo-4-nitropyridine N-oxide and 4,4'-dinitro-2,2'-bipyridine N,N'-dioxide, resp., via a tandem nucleophilic substitution - N-oxide redn. process is reported. The one-step prepn. of 4,4'-dihalo-2,2'-bipyridines from dihalopyridines via a Stille reaction is also described. 4,4'-Dibromo-2,2'-bipyridine undergoes selective mono- or disubstitution reactions under palladium catalysis. This short synthetic procedure is an efficient and reliable process for prepn. of conjugated pyridine and 2,2'-bipyridine building blocks for applications in coordination chem. and materials science. |
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