New Efficient Synthesis of 2-Substituted Benzothieno[3,2-<i>d</i>]pyrimidin-4(3<i>H</i>)-ones via a Tandem Aza-Wittig Reaction
作者:Ming-Wu Ding、Sheng-Zhen Xu、Yang-Gen Hu
DOI:10.1055/s-2006-950364
日期:——
with aryl isocyanates, reacted with secondary amines, phenols, or alkanols in the presence of a catalytic amount of potassium carbonate or sodium alkoxide to give 2-substituted benzothieno[3,2-d]pyrimidin-4(3H)-ones 6 in good yields. The reaction of carbodiimides 4 with primary amines RNH 2 (R ≠ H, Me) in the presence of sodium ethoxide selectively produced one regioisomer 8 via a base-catalyzed cyclization
1-Aryl-3-[2-(ethoxycarbonyl)benzothien-3-yl]carbodiimides 4,由亚氨基正膦3与芳基异氰酸酯的氮杂-维蒂希反应获得,在催化量的存在下与仲胺、酚或烷醇反应碳酸钾或醇钠以良好的收率得到 2-取代的苯并噻吩并[3,2-d]嘧啶-4(3H)-酮 6。碳二亚胺 4 与伯胺 RNH 2 (R ≠ H, Me) 在乙醇钠存在下的反应通过碱催化的环化机制选择性地产生一种区域异构体 8。然而,当伯胺 RNH 2 (R = H, Me) 在不存在乙醇钠的情况下通过直接环化机制使用时,获得了不同的区域异构体 9。