Potassium Carbonate → tert-butyl 3-(1H-indol-5-yl)-1,2,4-thiadiazol-5-ylcarbamate

Participants

Reaction Steps

To a mixture of tert-butyl (3-bromo-1,2,4-thiadiazol-5-yl)carbamate (100 mg, 0.359 mmol) and indole-5-boronic acid (57.9 mg, 0.359 mmol) in 1,4-dioxane (5 mL) was added Pd(PPh3)4 (20.77 mg, 0.017 mmol) and 1M aq K2CO3 solution (0.539 mL, 0.539 mmol). N2 gas was purged for 15 min. After 15 min, the reaction was heated at reflux for 4 h. The reaction mixture was cooled to RT and treated with H2O (5 mL), extracted with EtOAc (25 mL). The aqueous layer was back extracted with EtOAc (25 mL). The combined organic layers were dried over anhydrous Na2SO4 and concentrated. The crude was further purified by silica gel column chromatography (eluent: 10% EtOAc in petroleum ether) to afford tert-butyl (3-(1H-indol-5-yl)-1,2,4-thiadiazol-5-yl)carbamate (50 mg, 44.2%) as an off white solid. MS (ESI, pos. ion) m/z: 261 (M+1); 1H NMR (400 MHz, DMSO-d6): δ 12.40 (s, 1H), 11.31 (s, 1H), 8.35 (s, 1H), 7.91 (dd, J=1.2 Hz & 8.4 Hz, 1H), 7.46 (d, J=8.4 Hz, 1H), 7.41-7.40 (m, 1H), 6.35 (s, 1H), 1.52 (s, 9H).

Provenance & Evidence