Synthesis
In Example 1, 6-nitroindole was used as a raw material and reacted at 4.0 MPa hydrogen pressure and 80°C for 48 hours to carry out a hydrogenation reduction reaction. Other steps were the same as in Example 1, and 6-aminoindole was finally obtained in 94% yield. The specific operation was as follows: 16.44 mg (0.04 mmol) of silver 4,4'-dimethoxy-2,2'-bipyridine and 11.22 mg (0.1 mmol) of potassium tert-butoxide were dissolved in 1 mL of 1,4-dioxane and added to an autoclave. After stirring well, 165.15 mg (1 mmol) of m-nitroacetophenone was added and the reaction was stirred at 80 °C for 8 hours. At the end of the reaction, the reaction solution was extracted with water and dichloromethane to separate the organic phase. The organic phase was dried over anhydrous Na2SO4, and then subjected to filtration, rotary evaporation and chromatographic separation to obtain a yellow solid 3-acetanilide in 96% yield.
References
[1] Journal of Medicinal Chemistry, 1990, vol. 33, # 9, p. 2437 - 2451
[2] Patent: US2005/70534, 2005, A1. Location in patent: Page/Page column 14
[3] Patent: CN106748834, 2017, A. Location in patent: Paragraph 0016; 0033; 0036
[4] Molecules, 2014, vol. 19, # 1, p. 925 - 939
[5] Catalysis Communications, 2016, vol. 84, p. 25 - 29
