Convenient and Scalable Process for the Preparation of Indole via Raney Nickel–Catalyzed Hydrogenation and Ring Closure

X Guo, Z Peng, S Jiang, J Shen

Index: Guo, Xianghai; Peng, Zhiliang; Jiang, Shende; Shen, Jiaxiang Synthetic Communications, 2011 , vol. 41, # 14 p. 2044 - 2052

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Citation Number: 4

Abstract

Abstract An efficient and practical method for the synthesis of indole as a key starting material for many useful chemicals is described. Using 2-nitrotoluene as starting material, hydroxymethylation with formaldehyde under alkaline conditions gave 2-(2-nitrophenyl) ethanol on a large scale. Raney Ni catalyst was used for both reduction of the nitro group as well as for the indole formation. The overall yield was 78% from 2-nitrotoluene.