由2-(1-芳基-2-甲氧基乙烯基)-1-溴苯1制备4-芳基香豆素(= 4-芳基-1 H --2-苯并吡喃-1-酮)6。用BuLi和1-甲酰基哌啶连续处理这些溴苯乙烯,得到(E)-和(Z)-2-(1-芳基-2-甲氧基乙烯基)苯甲醛的混合物2。(Z)-异构体的水解 用HBr进行氧化,然后将所得的1 H -2-苯并吡喃-1-醇衍生物4(和5)氧化氯铬酸吡啶鎓(PCC ),得到所需的产物。
由2-(1-芳基-2-甲氧基乙烯基)-1-溴苯1制备4-芳基香豆素(= 4-芳基-1 H --2-苯并吡喃-1-酮)6。用BuLi和1-甲酰基哌啶连续处理这些溴苯乙烯,得到(E)-和(Z)-2-(1-芳基-2-甲氧基乙烯基)苯甲醛的混合物2。(Z)-异构体的水解 用HBr进行氧化,然后将所得的1 H -2-苯并吡喃-1-醇衍生物4(和5)氧化氯铬酸吡啶鎓(PCC ),得到所需的产物。
Synthesis of 3-Aryl-2-methoxyinden-1-one (<i>Z</i>)-Phenylhydrazones<i>via</i>Hydrobromic Acid-Mediated Cyclization of 2-(1-Aryl-2-methoxyethenyl)benzaldehyde Phenylhydrazones
2‐(1‐Aryl‐2‐methoxyethenyl)benzaldehydes 2, obtained by successive treatment of 1‐(1‐aryl‐2‐methoxyethenyl)‐2‐bromobenzenes 1 with BuLi and 1‐formylpiperidine, were transformed to the corresponding phenylhydrazones 3 on treatment with PhNHNH2. When these hydrazones were allowed to react with conc. HBr, cyclization, followed by dehydrogenation with air occurred, furnished 3‐aryl‐2‐methoxyinden‐1‐one