Preparation of Alkyl-Substituted Indoles in the Benzene Portion. Part 5. Efficient Preparative Procedure for 4-Substituted Indole Derivatives.
作者:Masahiro FUJI、Hideaki MURATAKE、Mitsutake MATSUME
DOI:10.1248/cpb.40.2338
日期:——
An effective and short synthetyic method for 4-substituted indole derivatives was developed based on the two sequential reactions, i.e. nucleophilic addition of carbanions to common precursor molecules, 3-(1, 3-dioxolan-2-yl)-1-[1-(phenylsulfonyl)- and 1-[(4-methylphenyl)sulfonyl]-3-pyrrolyl]-1-propanones (5a, b), followed by the acid-induced cyclization reaction of the resulting adducts to form 4-substituted 1-(phenylsulfonyl)- and 1-[(4-methylphenyl)-sulfonyl]indole derivatices (4a, b). This new method makes it possible resadily to synthesize imoportant intermediates, such as methyl 1-(phenylsulfonyl)indole-4-carboxylate (15), 4-formyl-1-(phenylsulfonyl)indole (16), and methyl 1-(phenylsulfonyl)indole-4-acetate (17) for numerous indole alkaloids, as well as a potent dopamine agonist, 4-[2-(diprophlamino)ethyl]indole (21).
开发了一种有效且简洁的4-取代吲哚衍生物合成方法,该方法基于两个连续反应,即碳阴离子对共同前体分子3-(1,3-二氧烷-2-基)-1-[1-(苯基磺酰基)-和1-[(4-甲基苯基)磺酰基]-3-吡咯基]-1-丙酮(5a,b)的亲核加成反应,随后是产物的酸催化环化反应,形成4-取代的1-(苯基磺酰基)-和1-[(4-甲基苯基)磺酰基]吲哚衍生物(4a,b)。该新方法使得合成重要中间体成为可能,比如甲基1-(苯基磺酰基)吲哚-4-羧酸酯(15)、4-甲酰基-1-(苯基磺酰基)吲哚(16)和甲基1-(苯基磺酰基)吲哚-4-乙酸酯(17),这些中间体对于众多吲哚生物碱以及一种强效的多巴胺激动剂4-[2-(二异丙氨基)乙基]吲哚(21)都具有重要意义。