Potassium Carbonate → HCID 20100022, compound

Participants

Reaction Steps

To the mixture of 5-bromo-1H-indole (1, 5 mmol, 1 equiv.), 3-tolylboronic acid (2, 5.5 mmol, 1.1 equiv.) and Pd(dppf)Cl2 (0.25 mmol, 0.05 equiv.) in 12 mL 1,4-dioxane was added 4 mL aqueous solution of K2CO3 (15 mmol, 3 equiv.). The mixture was stirred under argon for about 15 min then stirred under microwave in 130□ for about 25 min twice. On cooling, the solvent was evaporated and the resulting residue was extracted with CH2Cl2 (20 mL×3), the dichloromethane layer was washed with brine, dried (Na2SO4) and filtered. The residue obtained on removal of the solvent was purified by column chromatography on silica gel with EtOAc/hexane as eluting solvents to give the target compound 5-m-tolyl-1H-indole (3). Yield: 55.0%. 1H NMR (300 MHz, CDCl3): δ 2.31 (s, 3 H), 6.47 (s, 1 H), 6.92-7.12 (m, 2 H), 7.18-7.23 (m, 1 H), 7.29-7.35 (m, 4H), 7.74 (s, 1 H), 7.99 (br, 1H). 13C NMR (75 MHz, CDCl3) δ 21.5, 102.9, 111.1, 119.2, 121.9, 124.4, 124.8, 127.0, 128.2, 128.3, 128.5, 133.4, 135.2, 138.1, 142.5.

Provenance & Evidence