Diisopropylethylamine → 4-(tert-butyldimethylsilyloxy)-N1-(6-indolylcarbonyl)-N2-[1-(4-pyridyl)piperidin-4-yl]methoxycarbonyl-1,2-benzenediamine

Participants

Reaction Steps

A mixture of indole-6-carboxylic acid (71 mg, 0.44 mmol), bromotris(pyrrolidino)phosphonium hexafluorophosphate (204 mg, 0.44 mmol) and diisopropylethylamine (0.153 mL, 0.88 mmol) in dry methylene chloride (5 mL) was stirred 10 min. 4-(tert-Butyldimethylsilyloxy)-N2-[1-(4-pyridyl)piperidin-4-yl]methoxycarbonyl-1,2-benzenediamine (100 mg, 0.22 mmol) and N,N-dimethylformamide (2 mL) were added and the resulting mixture stirred 64 h at ambient temperature. Saturated aqueous sodium hydrogen carbonate solution (4 mL) was added, and the resultant mixture stirred for 30 min. The mixture was partitioned between ethyl acetate and water, the organic solution separated, dried (anhydrous magnesium sulfate), filtered, and concentrated in vacuo. The residue was chromatographed (silica gel, methylene chloride, 9:1 methylene chloride/methanol, 9:1:0.1 methylene chloride/methanol/ammonium hydroxide) to yield 55 mg (44%) of the title compound.

Provenance & Evidence