The synthesis of various chloroimidazo[4,5‐c]pyridines and related derivatives

Abstract

Abstract A new and convenient route to the synthesis of 4‐chloroimidazo[4,5‐c]pyridine (IV) has been devised. The preparation of 6‐chloroimidazo[4,5‐c]pyridine (IX) and 4,6‐dichloroimidazo[4, 5‐c]pyridine (XX) has been accomplished for the first time by ring closure of the requisite Chloro‐3.4‐diaminopyridines with ethyl orthoformate and acetic anhydride. Ring closure of 2,4,5‐triaminopyridine (XI) with ethyl orthoformate and acetic anhydride gave 6‐aminoimidazo[4, 5‐c]pyridine (XII). Imidazo[4, 5‐c]pyridine‐4‐thione (XXI has been prepared from 4‐chloroimidazo[4, 5‐c]pyridine.