Abstract
The title compound (8) was prepared by two improved methods. Initially, the 4-aminopiperidine derivative (11) was prepared by treatment of 4-aminopyridine (9) with the aralkyl chloride (5), followed by NaBH4 reduction of the resulting 4-aminopyridinium salt (10). Reaction of 11 with 2-chloronitrobenzene gave the intermediate (6). Subsequently, the key intermediate (7) was similarly prepared starting from 4-chloropyridine (12) via the pyridinium salt (14). In this method the target compound (8) was prepared in good yield with the technical advantage that the four steps (13→14→7→8) could be conveniently carried out in a one-pot procedure.
