Water → 2-Bromo-1-(9-bromo-5,7-dihydro-dibenzo[c,e]oxepin-3-yl)-ethanone

Participants

Reaction Conditions

Reaction Steps

To the solution of 3,9-dibromo-5,7-dihydro-dibenzo[c,e]oxepine (416 mg, 1.2 mmol) and tributyl(ethoxyvinyl)stannane (878 μl, 2.6 mmol) in dioxane (6 ml) was added PdCl2(PPh3)2 (30 mg). The mixture was heated at 80° C. for 16 hours and was cooled to 0° C. Water (2 ml) was added, followed by slow addition of NBS (464 mg, 2.6 mmol) over 5 minutes period. The mixture was stirred at 0° C. for additional 40 minutes, and the solvent was removed under reduced pressure. The mixture was diluted with EtOAc, and was washed with water and brine and dried with sodium sulfate. Concentration and purification by flash column chromatography (hexane/EtOAc) gave 2-bromo-1-(9-bromo-5,7-dihydro-dibenzo[c,e]oxepin-3-yl)-ethanone (120 mg). Pyrrolidine-1,2-dicarboxylic acid 2-[2-(9-bromo-5,7-dihydro-dibenzo[c,e]oxepin-3-yl)-2-oxo-ethyl]ester 1-tert-butyl ester: To the solution of (S)-Boc-Pro-OH (118 mg, 0.55 mmol) and triethylamine (65 μl, 0.46 mmol) in acetonitrile (2 ml) was added a solution of 2-bromo-1-(9-bromo-5,7-dihydro-dibenzo[c,e]oxepin-3-yl)-ethanone (120 mg, 0.31 mmol) in DMF (4 ml). The mixture was stirred for 10 hours, and the solvent was evaporated. The mixture was diluted with EtOAc, and washed with water and brine, and was dried with sodium sulfate. Concentration gave pyrrolidine-1,2-dicarboxylic acid 24-[2-(9-bromo-5,7-dihydro-dibenzo[c,e]oxepin-3-yl)-2-oxo-ethyl]ester 1-tert-butyl ester (160 mg). m/z: 553.8 (M+Na)+.

Provenance & Evidence