反应详情

4.77 g (0.02 mol) of 8-benzyloxy-2-methylimidazo[1,2-a]pyridine are stirred at 60° C. for 2.5 h in a Vilsmeier mixture of 20 ml of dimethylformamide and 2.3 ml of phosphorus oxychloride and the mixture is worked up in a customary manner using ice/water and potassium hydrogen carbonate. 8-Benzyloxy-2-methylimidazo[1,2-a]pyridine-3-carboxaldehyde of m.p. 105°-106° C. (from diisopropyl ether) is obtained. This compound is debenzylated analogously to Kaminski et al., J. Med. Chem. 28, 876 (1985), method H, to give the title compound of m.p. 251°-252° C.