Indole-3-acetamide → 3-(1H-Indol-3-yl)-4-[1-(2-trimethylsilanyl-ethoxymethyl)-1H-indol-7-yl]-pyrrole-2,5-dione

Participants

Reaction Steps

A 1.0 M solution of KOtBu in THF (8.1 mL, 8.1 mmol) was added to a solution of 2-(1H-indol-3-yl)-acetamide (417 mg, 2.4 mmol) and {1-(2-trimethylsilanyl-ethoxymethyl)-1H-indol-7-yl}-oxo-acetic acid methyl ester (774 mg, 2.32 mmol) in DMF (50 mL). The deep red-orange solution was stirred 16 h at room temperature and then 1 h at 65° C. The heating bath was removed and pH 7.0 buffer added. The mixture was poured into EtOAc, the layers separated and the EtOAc solution washed with 0.1 N HCl, water (3×), saturated aq NaHCO3 and brine (3×), dried (MgSO4), filtered and concentrated onto SiO2. Flash chromatography afforded 3-(1H-Indol-3-yl)-4-[1-(2-trimethylsilanyl-ethoxymethyl)-1H-indol-7-yl]-pyrrole-2,5-dione (141 mg, 13%) as a bright orange solid which was dried under vacuum overnight at 70° C., and 3-(1H-Indol-7-yl)-4-(1H-indol-3-yl)-pyrrole-2,5-dione (165 mg, 22%) as a bright red solid which was dried under vacuum overnight at 70° C.

Provenance & Evidence