A mixture of tert-butyl 4-(2,2-dibromovinyl)-5-methoxy-7-methyl-1H-indole-1-carboxylate (1.3 g, 2.92 mmol), 3,4-diaminobenzonitrile (700 mg, 5.26 mmol) and DABCO (819 mg, 7.30 mmol) in NMP (12 mL) was stirred at 110° C. for overnight. The reaction mixture was then cooled to room temperature, diluted with EtOAc, and washed with water. The organic layer was dried over magnesium sulfate, filtered and concentrated. The residue was purified using FCC eluting with heptane/EtOAc(60-80%) to provide the title compound. MS (ESI+) m/z 417.2 (M+H).
