1) 3-Nitro-4-chloro-5-bromopyridine (I) reacted with KSCN in glacial acetic acid to give 3-nitro-4-amino-5-bromopyridine, and 3-nitro-4-mercapto-5-bromopyridine was obtained by the reacion of (I) and KSH in methanol. 2) 7-Bromopyrido [3, 4-d] thiazole derivatives were synthesized from 3-nitro-4-mercapto-5-bromopyridine through reduction followed by cyclization.
