Ethyl Acetate → tert-butyl 3-cyclohexyl-2-phenyl-1H-indole-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 2-bromo-3-cyclohexyl-1H-indole-6-carboxylate (from Step 2) in DME and EtOH (0.2 M, 3:1, v/v) was added phenyl-boronic acid (1.2 eq.) followed by 2 M aqueous Na2CO3 (8.5 eq.). The mixture was degassed with argon, then Pd(PPh3)4 (0.1 eq.) was added and the mixture stirred under argon at 80° C. for 1 h. After cooling to RT, EtOAc was added and the organic layer washed with HCl solution (1N, ×2) and brine. The organic layer was dried over Na2SO4 and evaporated and the residue purified by silica gel chromatography (Flashmaster Personal, PE:EtOAc, 20:1) to give the title compound (90%). 1H NMR (400 MHz, DMSO-d6, 300 K) δ 1.21-1.48 (m, 3H), 1.56 (s, 9H), 1.65-1.80 (m, 5H), 1.90-2.05 (m, 2H), 2.79-2.95 (m, 1H), 7.50-7.57 (m, 6H), 7.40-7.50 (m, 1H), 7.79 (d, J 7.6, 1H), 7.94 (s, 1H); MS (ES+) m/z 376 (M+H)+.

Provenance & Evidence