Tributylphosphine → 6-Bromo-5-(1-isopropyl-piperidin-4-yloxy)-1H-indole-2-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To the suspension of 0.25 g (0.88 mmol) 6-bromo-5-hydroxy-1H-indole-2-carboxylic acid ethyl ester in 5 mL tetrahydrofuran, 0.15 g (1.05 mmol) 1-isopropyl-piperidin-4-ol (commercially available) and 0.28 g (1.07 mmol) tributylphosphine were added. The suspension was cooled to 0° C., 0.244 g (1.06 mmol) di-tert-butyl azodicarboxylate was added and the reaction was allowed to reach room temperature. After 48 hours the suspension was filtered and the filtrate was evaporated. The residue was flash-chromatographed on silica gel with a gradient of dichloromethane:methanol (100:0 to 60:40 v/v) to give 0.20 g (55%) of the product as a light yellow foam. MS (m/e): 409.0 (M−H+, 100%).

Provenance & Evidence