Synthesis and Reactivity of 4-(2-Chloro-5-nitrophenyl)-1,2,3-thiadiazole. A Novel One-pot Synthesis of N-Substituted Indole-2-thiols

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• 作者：Dmitry A. Androsov ; Douglas C. Neckers
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：July 6, 2007
• 年：2007
• 卷：72
• 期：14
• 页码：5368 - 5373
• 全文大小：169K
• 年卷期：v.72,no.14(July 6, 2007)
• ISSN：1520-6904

文摘

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4-(2-Chloro-5-nitrophenyl)-1,2,3-thiadiazole undergoes ring opening to produce a thioketene intermediatethat reacts with an O- or N-nucleophile, forming an ester or an amide of the aryl-substituted thioaceticacid. Intermolecular cyclization of the thioacetic acid derivative via nucleophilic substitution of halogenin the aromatic ring gives an N-substituted indole-2-thiol (in case of an N-nucleophile) or a 2-alkoxy-substituted benzo[b]thiophene (in case of an O-nucleophile). The reaction is also applicable to the synthesisof heterocyclic analogues of N-substituted indole-2-thiols: 1-butyl-1,3-dihydropyrrolo[2,3-b]pyridine-2-thione was synthesized as an example. In the presence of potassium thioacetate (an S-nucleophile)4-nitro-2-(1,2,3-thiadiazol-4-yl)benzenethiol is formed more quickly than thiadiazole ring opening occurs,making the heterocyclic ring tolerant toward the base.