1186663-64-8

General procedure for the synthesis of 3-bromo-4-cyano-1H-indole from 4-cyanoindole: Example 146 Preparation of 1-methyl-3-[3-(4-methylpyridin-3-yl)-2-oxoimidazolidin-1-yl]-1H-indole-4-carbonitrile (146A) Step 1: Synthesis of the intermediate 3-bromo-1H-indole-4-carbonitrile (I-146a) A DMF solution of bromine (0.796 g, 4.975 mmol) was slowly added to a stirred DMF solution (15 mL) of 1H-indole-4-carbonitrile (700 mg, 4.9295 mmol) and the reaction was carried out at room temperature. The reaction mixture was stirred continuously at room temperature for 2 h. The reaction progress was monitored by thin layer chromatography (TLC, unfolding agent was 10% ethyl acetate in hexane solution). Upon completion of the reaction, the mixture was poured into ice water containing 0.5% ammonia and 0.5% sodium bisulfite. The precipitated solid was collected by filtration, washed with cold water and dried to give 850 mg of the target product 3-bromo-1H-indole-4-carbonitrile in 78.41% yield. 1H NMR (DMSO-D6, 300 MHz): δ 12.1 (s, 1H), 8.02-7.49 (m, 3H), 7.42-7.2 (m, 1H).

[1] Patent: US2010/331326, 2010, A1. Location in patent: Page/Page column 58
[2] Patent: WO2010/149755, 2010, A1. Location in patent: Page/Page column 148