4-溴苯乙酸叔丁酯

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of 4-bromophenylacetic acid (5.00 g, 23.2 mmol) in tBuOAc (75 mL) was added BF3.OEt2 (2.95 mL, 23.2 mmol). The mixture was allowed to stir overnight at room temperature and poured into H2O. The aqueous phase was extracted with EtOAc. The organic phase was washed with sat. aq NaHCO3, dried over anhydrous Na2SO4, and concentrated in vacuo. Purification by flash chromatography on silica gel (0% to 100% EtOAc in hexanes) provided the title compound. 1H NMR (500 MHz, CDCl3): δ 7.48 (d, J=8.0 Hz, 2 H), 7.19 (d, J=8.0 Hz, 2 H), 3.52 (s, 2 H), 1.48 (s, 9 H). The aqueous phase was extracted with EtOAc The organic phase was washed with sat. aq NaHCO3 dried over anhydrous Na2SO4 concentrated in vacuo Purification by flash chromatography on silica gel (0% to 100% EtOAc in hexanes)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Lithium bis(trimethylsilyl)amide (1.06 M in THF; 18.1 mL, 19.2 mmol) was added dropwise over 10 min to a stirred solution of tert-butyl (4-bromophenyl)acetate (4.92 g, 18.1 mmol) in THF (50 mL) at −78 ° C. under nitrogen. On completion of addition stirring was continued at −78 ° C. for 30 min then benzyl-2-bromoacteate (4.97 g, 3.44 mL, 21.7 mmol) was added dropwise over 5 min. The reaction was allowed to warm slowly to room temperature over 4 h then saturated ammonium chloride solution (50 mL) was added and the resulting suspension extracted with ethyl acetate (3×100 mL). The organic phases were combined, dried (magnesium sulfate) and evaporated to dryness. The residue was chromatographed on silica gel (10% diethyl ether: cyclohexane) to give the title compound as a colourless oil (6.26 g, 82%). LC/MS: 4.02 min; z/e 419 and 421, calcd (M+1) 419 and 421. 1H NMR (400 MHz: CDCl3): 7.40 (2H), 7.30 (5H), 7.10 (2H), 5.10 (2H), 3.90 (1H), 3.15 (1H), 2.65 (1H), 1.35 (9H). On completion of addition the resulting suspension extracted with ethyl acetate (3×100 mL) dried (magnesium sulfate) evaporated to dryness The residue was chromatographed on silica gel (10% diethyl ether: cyclohexane)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of 4-bromophenylacetic acid (5.00 g, 23.2 mmol) in tBuOAc (75 mL) was added BF3.OEt2 (2.95 mL, 23.2 mmol). The mixture was allowed to stir overnight at room temperature and poured into H2O. The aqueous phase was extracted with EtOAc. The organic phase was washed with sat. aq NaHCO3, dried over anhydrous Na2SO4, and concentrated in vacuo. Purification by flash chromatography on silica gel (0% to 100% EtOAc in hexanes) provided the title compound. 1H NMR (500 MHz, CDCl3): δ 7.48 (d, J=8.0 Hz, 2 H), 7.19 (d, J=8.0 Hz, 2 H), 3.52 (s, 2 H), 1.48 (s, 9 H). The aqueous phase was extracted with EtOAc The organic phase was washed with sat. aq NaHCO3 dried over anhydrous Na2SO4 concentrated in vacuo Purification by flash chromatography on silica gel (0% to 100% EtOAc in hexanes)