2-Isopropoxy-6-(tributylstannyl)pyridine → tert-butyl (3-(3-(6-isopropoxypyridin-2-yl)-1-tosyl-1H-indol-5-yl)-1,2,4-thiadiazol-5-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

A mixture of tert-butyl (3-(3-iodo-1-tosyl-1H-indol-5-yl)-1,2,4-thiadiazol-5-yl)carbamate (0.6 g, 1.0 mmol) and 2-isopropoxy-6-(tributylstannyl)pyridine (0.429 g, 1.0 mmol) in DMF (10 mL) was bubbled N2 gas for 15 min. To the above mixture, CuI (95 mg, 0.5 mmol.) and Pd(PPh3)4 (12 mg, 0.1 mmol) were added and N2 gas was bubbled for another 15 min. The reaction was heated at 90° C. for 1 h. The reaction mixture was quenched with H2O (10 mL) and extracted with CHCl3 (2×25 mL). The organic layer was dried over anhydrous Na2SO4 and concentrated under reduced pressure. The crude was purified by neutral alumina column chromatography (eluent: 20% EtOAc in petroleum ether) to give tert-butyl (3-(3-(6-isopropoxypyridin-2-yl)-1-tosyl-1H-indol-5-yl)-1,2,4-thiadiazol-5-yl)carbamate (0.35 g, 57.4%). MS (ESI, pos. ion) m/z: 606.4 (M+1); 1H NMR (DMSO-d6, 400 MHz): δ 9.33 (s, 1H), 8.52 (s, 1H), 8.16-8.08 (m, 2H), 7.97 (d, J=8 Hz, 2H), 7.76 (t, J=7.6 Hz, 1H), 7.63 (d, J=7.6 Hz, 2H), 7.40 (d, J=8.4 Hz, 1H), 6.69 (d, J=8 Hz, 1H), 5.52-5.49 (m, 1H), 2.30 (s, 3H), 1.40 (d, J=6 Hz, 6H).

Provenance & Evidence