Synthesis of 4-Amino-3-pyridinyl and 4-Amino-5-pyrimidinyl Aryl Ketones and Related Compounds<i>via</i>an<i>ortho</i>-Lithiation Reaction
作者:Rumen Radinov、Marietta Haimova、Ekaterina Simova
DOI:10.1055/s-1986-31817
日期:——
4-Chloropyridine and 4,6-dïchloropyrimidine react regioselectively with lithium diisopropylamide to give 4-chloro-3-lithiopyridine and 4,6-dichloro-5-lithiopyrimidine, respectively. These intermediates react with benzaldehydes to give (4-chloro-3-pyridinyl) and 4,6-dichloro-5-pyrimidinyl)-arylmethanols which are oxidized to the corresponding ketones by chromium(VI) oxide in acetone. These compounds ran be nucleophilically substituted with ammonia or primary amines to give 4-amino-3-aroylpyridines or amino-5-aroylpyridines. The 3 aroyl-4-chloropyridines can also be easily converted into 3-aroyl-4(1H)-pyridinones.
4-氯吡啶和4,6-二氯嘧啶与二异丙基铵氟化锂发生区域选择性反应,分别生成4-氯-3-锂吡啶和4,6-二氯-5-锂嘧啶。这些中间体与苯甲醛反应生成(4-氯-3-吡啶基)和4,6-二氯-5-嘧啶基)-芳基甲醇,这些化合物在丙酮中被六氧化铬氧化为相应的酮。这些化合物可以与氨或一元胺进行亲核取代反应,生成4-氨基-3-芳酰吡啶或氨基-5-芳酰吡啶。3-芳酰-4-氯吡啶也可以容易地转化为3-芳酰-4(1H)-吡啶酮。