Muscarinic M3 antagonists

The copper-catalyzed amination of bromopyridine 29 was reported by workers at Merck on route to the synthesis of muscarinic (M3) antagonist 31 <01TL3251>. Interestingly, an uncatalyzed amination of 3-nitropyridines has also been reported <01JCS(P1)376>. Other metal mediated processes have been used to access pyridines with important biological activity as well <0lJOC605x01TL6811>. 

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