ethyl 2-(4-bromophenyl)acetate

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 2.0 M LDA in heptane/THF/ethylbenzene (6.0 mL, 12 mmol) was slowly added to a solution of ethyl (4-bromophenyl)acetate (2.43 g, 10.0 mmol) in THF (20 mL) at −78° C. and then the mixture was stirred for 30 min. Methyl iodide (0.93 mL, 15 mmol) was added at −78° C. and then the reaction was stirred for an additional 30 min. Saturated NH4Cl aq. was added to quench the reaction. The mixture was extracted with ethyl acetate. The combined organic layers were washed with water and brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography on a silica gel column with ethyl acetate in hexane (0-10%) to afford the desired product (2.0 g). the reaction was stirred for an additional 30 min to quench the reaction The mixture was extracted with ethyl acetate The combined organic layers were washed with water and brine dried over Na2SO4 filtered concentrated under reduced pressure The residue was purified by flash chromatography on a silica gel column with ethyl acetate in hexane (0-10%)

反応条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a cold solution (−78° C.) of 15 g (62 mmol) of ethyl (4-bromophenyl)acetate (Compound A) in 150 ml of CH2Cl2 was added dropwise (over a span of 1 hour) 65 ml (65 mmol) of diisobutylaluminum hydride (DIBAL-H, 1M solution in hexane). After the DIBAL-H addition was complete, the reaction was stirred at −78° C. for an additional hour. The reaction was quenched by the dropwise addition of methanol (10 ml), followed by water (10 ml) and 10% HCl (40 ml). The mixture was then warmed to 0° C., stirred for 10 minutes and then washed with water (15 ml), 10% aqueous NaHCO3 (10 ml) and brine (10 ml). The organic phase was dried over MgSO4 and the solvent distilled off at ambient temperature to give crude (4-bromophenyl)acetaldehyde. To a cold solution (0° C.) of this crude aldehyde in 150 ml of CH2Cl2 was added a solution of 26 g (74.6 mmol) of (carbethoxymethylene)triphenylphosphorane in 50 ml of CH2Cl2. The mixture was stirred for 16 hours, concentrated in vacuo and purified by flash chromatography (silica, 10% EtOAc-hexane) to give ethyl 4-(4-bromophenyl)but-2-enoate as a mixture of E:Z isomers. This isomeric mixture was dissolved in 150 ml of EtOAc and hydrogenated over 1 g of 10% Pd/C for 6 hours. The catalyst was filtered off and the filtrate concentrated in vacuo to give the title compound as a white solid. The reaction was quenched by the dropwise addition of methanol (10 ml) The mixture was then warmed to 0° C. stirred for 10 minutes washed with water (15 ml), 10% aqueous NaHCO3 (10 ml) and brine (10 ml) The organic phase was dried over MgSO4 the solvent distilled off at ambient temperature

反応条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a cold solution (−78° C.) of 15 g (62 mmol) of ethyl (4-bromophenyl)acetate (Compound A) in 150 ml of CH2Cl2 was added dropwise (over a span of 1 hour) 65 ml (65 mmol) of diisobutylaluminum hydride (DIBAL-H, 1M solution in hexane). After the DIBAL-H addition was complete, the reaction was stirred at −78° C. for an additional hour. The reaction was quenched by the dropwise addition of methanol (10 ml), followed by water (10 ml) and 10% HCl (40 ml). The mixture was then warmed to 0° C., stirred for 10 minutes and then washed with water (15 ml), 10% aqueous NaHCO3 (10 ml) and brine (10 ml). The organic phase was dried over MgSO4 and the solvent distilled off at ambient temperature to give crude (4-bromophenyl)acetaldehyde. To a cold solution (0° C.) of this crude aldehyde in 150 ml of CH2Cl2 was added a solution of 26 g (74.6 mmol) of (carbethoxymethylene)triphenylphosphorane in 50 ml of CH2Cl2. The mixture was stirred for 16 hours, concentrated in vacuo and purified by flash chromatography (silica, 10% EtOAc-hexane) to give ethyl 4-(4-bromophenyl)but-2-enoate as a mixture of E:Z isomers. This isomeric mixture was dissolved in 150 ml of EtOAc and hydrogenated over 1 g of 10% Pd/C for 6 hours. The catalyst was filtered off and the filtrate concentrated in vacuo to give the title compound as a white solid. The reaction was quenched by the dropwise addition of methanol (10 ml) The mixture was then warmed to 0° C. stirred for 10 minutes washed with water (15 ml), 10% aqueous NaHCO3 (10 ml) and brine (10 ml) The organic phase was dried over MgSO4 the solvent distilled off at ambient temperature

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Employing the same general procedure as for the preparation of ethyl (4-bromophenyl)acetate (Compound A), 100 g (463 mmol) of 3-bromophenylacetic acid was converted into the title compound (yellow oil) using 2 g of conc. H2SO4 and 500 ml of ethanol.

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Employing the same general procedure as for the preparation of ethyl (4-bromophenyl)acetate (Compound A), 100 g (463 mmol) of 3-bromophenylacetic acid was converted into the title compound (yellow oil) using 2 g of conc. H2SO4 and 500 ml of ethanol.

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of 43 g (200 mmol) of 4-bromophenylacetic acid and 0.2 g of conc. H2SO4 in 470 ml of ethanol was refluxed for 16 hours. The reaction mixture was cooled to ambient temperature, stirred with 6 g of solid K2CO3 for 30 minutes and then filtered. The filtrate was concentrated in vacuo, diluted with Et2O (200 ml), washed with 10% aqueous NaHCO3 (10 ml) and brine (10 ml), dried over MgSO4 and concentrated in vacuo to give the title compound as a colorless oil. filtered The filtrate was concentrated in vacuo diluted with Et2O (200 ml) washed with 10% aqueous NaHCO3 (10 ml) and brine (10 ml) dried over MgSO4 concentrated in vacuo