6-溴-4-羟基-1,7-萘啶的合成研究

Synthesis of 6-Bromo-1,7-naphthyridin-4-ol

以5-氨基-2-溴吡啶氮氧化物(2)为原料,与乙氧亚甲基丙二酸二乙酯(EMME)经缩合、环合得6-溴-3-羧酸乙基-4-羟基-1-萘啶-7-氧化物(4),4经混酸脱羧后,铁粉还原,得到6-溴-4-羟基-1,7-萘啶(1),关键中间体与产物的结构经^1H NMR、^13C NMR和MS分析确证,总收率61%。该工艺反应条件温和、操作方便,具有一定的应用价值。

6-Bromo-3-(ethoxycarbonyl)-4-hydroxy-1,7-naphthyridine-7-oxide(4)was obtained from the condensation reaction of 5-amino-2-bromopyridine 1-oxide(2)with EMME followed by cyclization.The title compound 1 in overall yield of 61%was synthesized by decarboxylic reaction of form 4 with AcOH/HCl,followed by reduction with iron.The structures of key intermediates and the product were characterized by^1 H NMR,^13C NMR and MS spectra.This synthetic route has advantages including mild reaction condition,satisfactory yields and easy operation.Therefore it could be prospected in application.