Reactions of 4-hydroxy-5,6,7,8-tetrafluorocoumarin derivatives with S-nucleophiles
作者:I.T Bazyl′、S.P Kisil′、Ya.V Burgart、V.I Saloutin
DOI:10.1016/s0022-1139(99)00210-9
日期:2000.4
In the reactions with o-aminothiophenol, 4-hydroxy-(3-(imino)acetyl)-5,6,7,8-tetrafluorocoumarins give products of S-substitution at the C-7 atom. 7-Substituted 5,6,8-trifluorocoumarins form benzothiazole as a result of heterocyclic ring opening; 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorochromone undergoes acid splitting to 2-(2-hydroxy-3,4,5,6-tetrafluorophenyl)benzothiazole. Under alkaline conditions
与反应ø -氨基苯硫酚,4 -羟基-(3 -(亚氨基)乙酰基)-5,6,7,8-四氟香豆素在C-7原子处产生S取代的产物。由于杂环开环,7-取代的5,6,8-三氟香豆素形成苯并噻唑;3-乙氧基羰基-2-甲基-5,6,7,8-四氟色酮经历酸裂解反应生成2-(2-羟基-3,4,5,6-四氟苯基)苯并噻唑。在碱性条件下,S-取代的香豆素分解为苯乙酮。在酸性介质中,4-羟基-3-亚氨基乙酰基-5,6,8-三氟-7-(2-氨基苯硫基)香豆素得到7-(2-氨基苯硫基)-2-甲基-5,6,8-三氟色酮。从7-(2-氨基苯硫基)-4-羟基-5,6,8-的缩合分离出4-羟基-5,6-二氟-2-H-吡喃并[6,5-a]吩噻嗪-2-one。 NaH存在下的三氟香豆素。