6127-18-0

The general procedure for the synthesis of 4-bromo-2-methyl-1H-indole using the compound (CAS:1232861-11-8) as starting material was as follows: sodium hydroxide (4.01 g, 0.1 mol) was added to a mixture of methanol (80 mL) and water (40 mL) of intermediate 3 (7.0 g, 20.1 mmol). The reaction mixture was stirred at 50 °C for 6 hours. Upon completion of the reaction, the mixture was cooled to room temperature and concentrated under reduced pressure. The residue was extracted with dichloromethane (3 x 50 mL). The organic layers were combined, washed sequentially with water and saturated saline, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by fast column chromatography (silica gel as stationary phase, petroleum ether/ethyl acetate=5:1 as eluent) to afford the target product 4-bromo-2-methyl-1H-indole 4 (3.0 g, 71% yield). Low resolution mass spectrometry (LRMS) (M+H+) m/z: calculated value 209.98; measured value 210.12.

[1] Patent: WO2014/15291, 2014, A1. Location in patent: Page/Page column 186; 187
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