反应详情

In Scheme I is described the preparation of pyridine intermediates (5), (6), and (7). In Scheme I, Step 1,3-bromopyridine (1) is oxidized to 3-bromo-pyridine-N-oxide (2). In Scheme I, Step 2, cyanide substitution gives 3-bromo-pyridine-2-carbonitrile (3). The nitrile of formula (3) is hydrolyzed in Step 3 to the carboxylic acid and esterified with acid catalysis to the ester of formula (4). In Scheme I, Step 4, the ester is reduced to the pyridinylmethanol of formula (5) using sodium borohydride. The pyridinylmethanol is converted to the mesylate of formula (6) with methanesulfonyl chloride (Step 5) or to the pyridinylmethyl chloride of formula (7) using thionyl chloride (Step 6).