Potassium Carbonate → 1,7-Bis-(1H-indol-5-yl)-isoquinoline

Beteiligte Stoffe

Reaktionsschritte

A mixture of 7-bromo-1-chloroisoquinoline (0.20 g, 2.1 mmol), 5-indoleboronic acid (0.80 g, 5.0 mmol), tetrakis(triphenylphosphene)palladium (0.19 g, 0.16 mmol), potassium carbonate (2.1 mL, 2 M, 4.1 mmol), N,N-dimethylformamide (11 mL) was stirred while purging the headspace with argon for 30 min. The mixture was then brought to reflux for 16 h before being allowed to cool to RT. The mixture was filtered through a bed of silica gel, diluted with water (50 mL), and extracted with ethyl acetate (50 mL). The organic layer was separated and washed with NaOH (2×20 mL, 10% aq.), water (5×30 mL, until refractive changes were no longer seen at the organic-aqueous interface), and ammonium chloride (20 mL, sat.). The organic layer was then adsorbed onto silica gel and flash-chromatographed (ethyl acetate/hexanes) to afford 0.29 g (39%) of a yellow solid. MS (ESI): calculated for C25H17N3, 359.1. found 360.2 [M+H]+382.1 [M+Na]+, and 358.0 [M−H]−. 1H NMR (500 MHz, DMSO-d6) δ 6.46-6.50 (m, 1H) 6.52-6.59 (m, 1H) 7.34-7.36 (m, 1H) 7.36-7.41 (m, 2H) 7.42-7.52 (m, 3H) 7.58 (d, J=8.30 Hz, 1H) 7.81 (dd, J=5.49, 5.00 Hz, 2H) 7.92 (s, 1H) 8.08-8.17 (m, 2H) 8.33 (s, 1H) 8.54 (d, J=5.61 Hz, 1H) 11.18 (br. s., 1H) 11.30 (br. s., 1H) ppm.

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