Sodium Carbonate → methyl 1-(2-tert-butoxy-2-oxoethyl)-3-cyclohexyl-2-(3-formyl-2-furyl)-1H-indole-6-carboxylate

Participants

Reaction Steps

To a solution of methyl 2-bromo-1-(2-tert-butoxy-2-oxoethyl)-3-cyclohexyl-1H-indole-6-carboxylate (prepared as described in Example 1, Step 1) in dioxane (0.04 M) was added Na2CO3 (5 eq, 2 M aqueous solution), 3-formylfuran-2-boronic acid (1.4 eq) and bis(triphenylphosphine)palladium(II) dichloride (0.2 eq). The mixture was heated at reflux for 20 mins, at which point the heat was removed and the reaction cooled slightly to allow addition of a further 1 eq of boronic acid. The reaction was then heated for a further 1 h at reflux. Again, the reaction was cooled slightly to allow addition of a further 0.5 eq of boronic acid. After heating for a further 30 mins, the reaction was allowed to cool to RT, filtered and the filtrate diluted with EtOAc. The organic phase was washed with H2O and dried (Na2SO4) before being filtered and concentrated in vacuo. The crude was purified by flash chromatography (10-20% EtOAc/PE) to afford the title compound as an oil (38%); MS (ES+) m/z 466 (M+H)+, 488 (M+Na)+.

Provenance & Evidence