反应详情

4.77 g of 8-benzyloxy-2-methylimidazo[1,2-a]pyridine are stirred in a Vilsmeier mixture of 20 ml of dimethylformamide and 2.3 ml of phosphoryl chloride for 2.5 h at 60° C., and are worked up mit ice/water and potassium hydrogen carbonate in a usual manner. 8-Benzyloxy-2-methylimidazo[1,2-a]pyridine-3-carboxaldehyde of m.p. 105°-106° C. (from diisopropylether) is obtained, which is debenzylated according to Kaminski et al., J. Med. Chem. 28, 876 (1985), method H, to yield 3-formyl-8-hydroxy-2-methylimidazo[1,2-a]pyridine of m.p. 251°-252° C.