鄰硝基甲苯類化合物和甲酰胺縮醛（如DMFDMA）縮合得到trans-β-二烷基胺基-2-硝基苯乙烯，接著還原得到吲哚類化合物的反應(yīng)。

此反應(yīng)原料鄰硝基甲苯(衍生物)易得，反應(yīng)條件溫和，產(chǎn)率較高，因此常用作Fischer吲哚合成的替代方法。還原方法一般通過加氫，但當(dāng)分子內(nèi)有敏感官能團(tuán)（比如：Br，I都可或烯烴等）存在時(shí)可通過化學(xué)還原如：NH2NH2-RaneyNi, 鐵粉，TiCl3, 鋅粉還原得到吲哚。

反應(yīng)機(jī)理

首先二甲基甲酰胺二甲縮醛，甲氧基負(fù)離子離去，產(chǎn)生一個(gè)活性更強(qiáng)的中間體。它受到鄰硝基甲苯甲基氫去質(zhì)子化形成的碳負(fù)離子的進(jìn)攻，失去甲醇，得到上述烯胺。這一步的產(chǎn)物烯胺類似于一種分別在兩側(cè)連有吸電子和供電子取代基的烯烴（Push-pull olefin），極性較強(qiáng)，而且常因分子中較大的共軛范圍而呈深紅色。反應(yīng)的第二步中硝基被還原為氨基，接著環(huán)化并消除得到最終產(chǎn)物。

反應(yīng)實(shí)例

Kozikowski, A. P.; Ishida, H.; Chen, Y.-Y. J. Org. Chem. 1980, 45, 3350–3352

Batcho, A. D.; Leimgruber, W. Org. Synth. 1985, 63, 214–225

Tetrahedron Lett. 2007, 48, 7990–7993

Org. Process Res. Dev. 2012, 16, 1897–1904

在不加入吡咯烷時(shí)此反應(yīng)通常反應(yīng)較慢，加入吡咯烷后反應(yīng)速率會(huì)迅速提高，因?yàn)檫量┩橄群虳MFDMA反應(yīng)，產(chǎn)生一個(gè)活性更強(qiáng)的試劑。

To a solution of 4-methoxy-2-nitrotoluene 1 (17.9 g, 0.107 mol) in 200 mL of dry DMFwas added DMFDMA (42 mL, 0.316 mol) and pyrrolidine (10 mL, 0.12 mmol).  The mixture was heated at 105 ℃ for 19 h under nitrogen, then cooled, diluted with water and extracted with ether (8×50 mL).  The ether layer was extracted with water (3×25 mL), dried with sodiumsulfate, and concentrated to give a deep red oil 2 which was dissolverin ethyl acetate (150 mL), and to the solution was added 10% palladium oncarbon (1.8 g).  Hydrogenation at 50 p.s.i. with shaking for 3h and then filtration through celite gave a light brown filtrate.  This filtrate is evaporated to purple oil,which was purified by chromatography on silica gel (eluent: DCM) to give6-methoxyindole Yield: 76%

編譯自：J.J. Li, Name Reactions: A Collection of Detailed Mechanisms and Synthetic Applications,  Batcho–Leimgruber indole synthesis，page34-35.