专利号:US-5144038-A 优先权日:1990-07-17 标题:Process for the production of 2-hydroxy-3-halo-5-nitropyridines 发明人:WORSCH DETLEV 权利人:LONZA AG 摘要:A process for the production of 2-hydroxy-3-halo-5-nitropyridines, in which a 5-halo-6-hydroxynicotinic acid is nitrated in the end product. The resultant pyridines form valuable intermediate products for active ingredient synthesis.