(a) Propose a mechanism for the reaction of 2-bromopyridine with sodium amide to give 2-aminopyridine. (b) When...

Question:

(a) Propose a mechanism for the reaction of 2-bromopyridine with sodium amide to give 2-aminopyridine.
(b) When 3-bromopyridine is used in this reaction, stronger reaction conditions are required and a mixture of 3-aminopyridine and 4-aminopyridine results. Propose a mechanism to explain this curious result.