METHYL 2,4-DIBROMOBENZOATE

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

実験手順: To stirred mixture of ZnBr2 (40.0 g, 176 mmol, 5.44 equiv, 99%) in THF (100 mL) under nitrogen at 0° C. was added dropwise EtMgBr (60 mL, 3 M in THF). After 0.5 h at 0° C., the temperature was lowered to −78° C. and PdCl2(dppf) (3.72 g, 5.03 mmol, 0.16 equiv, 99%) was added followed by the dropwise addition of a solution of methyl 2,4-dibromobenzoate (compound 204.1, 10.0 g, 32.3 mmol, 1.00 equiv, 95%) in THF (200 mL). The reaction was stirred overnight at room temperature, then carefully quenched with water followed by HCl (aq., 1 M). The resulting mixture was extracted with 3×500 mL of ethyl acetate, and the combined organic layers were washed with 3×50 mL of brine, dried over anhydrous sodium sulfate, and concentrated in vacuo. The residue was purified using silica gel column chromatography with ethyl acetate/petroleum ether (1:60) as eluent to furnish 6.30 g (96%) of methyl 2,4-diethylbenzoate as a colorless oil was lowered to −78° C. The reaction was stirred overnight at room temperature carefully quenched with water The resulting mixture was extracted with 3×500 mL of ethyl acetate the combined organic layers were washed with 3×50 mL of brine dried over anhydrous sodium sulfate concentrated in vacuo The residue was purified

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

実験手順: A solution of 2,4-dibromobenzoic acid (52.0 g, 176 mmol, 1.00 equiv, 95%) and sulfuric acid (20 mL) in methanol (400 mL) was stirred at 90° C. overnight. After cooling to room temperature, the mixture was concentrated under reduced pressure. The residue was diluted with 500 mL of ethyl acetate and washed with 3×100 mL of H2O followed by 1×100 mL of NaHCO3 (aq., sat. Note: gas evolution occurs). The organic layer was dried over anhydrous sodium sulfate and concentrated in vacuo. This resulted in 45.0 g (78%) of methyl 2,4-dibromobenzoate as a yellow oil. the mixture was concentrated under reduced pressure The residue was diluted with 500 mL of ethyl acetate washed with 3×100 mL of H2O The organic layer was dried over anhydrous sodium sulfate concentrated in vacuo This resulted in 45.0 g (78%) of methyl 2,4-dibromobenzoate as a yellow oil

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

実験手順: To stirred mixture of ZnBr2 (40.0 g, 176 mmol, 5.44 equiv, 99%) in THF (100 mL) under nitrogen at 0° C. was added dropwise EtMgBr (60 mL, 3 M in THF). After 0.5 h at 0° C., the temperature was lowered to −78° C. and PdCl2(dppf) (3.72 g, 5.03 mmol, 0.16 equiv, 99%) was added followed by the dropwise addition of a solution of methyl 2,4-dibromobenzoate (compound 204.1, 10.0 g, 32.3 mmol, 1.00 equiv, 95%) in THF (200 mL). The reaction was stirred overnight at room temperature, then carefully quenched with water followed by HCl (aq., 1 M). The resulting mixture was extracted with 3×500 mL of ethyl acetate, and the combined organic layers were washed with 3×50 mL of brine, dried over anhydrous sodium sulfate, and concentrated in vacuo. The residue was purified using silica gel column chromatography with ethyl acetate/petroleum ether (1:60) as eluent to furnish 6.30 g (96%) of methyl 2,4-diethylbenzoate as a colorless oil was lowered to −78° C. The reaction was stirred overnight at room temperature carefully quenched with water The resulting mixture was extracted with 3×500 mL of ethyl acetate the combined organic layers were washed with 3×50 mL of brine dried over anhydrous sodium sulfate concentrated in vacuo The residue was purified

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

実験手順: A solution of 2,4-dibromobenzoic acid (52.0 g, 176 mmol, 1.00 equiv, 95%) and sulfuric acid (20 mL) in methanol (400 mL) was stirred at 90° C. overnight. After cooling to room temperature, the mixture was concentrated under reduced pressure. The residue was diluted with 500 mL of ethyl acetate and washed with 3×100 mL of H2O followed by 1×100 mL of NaHCO3 (aq., sat. Note: gas evolution occurs). The organic layer was dried over anhydrous sodium sulfate and concentrated in vacuo. This resulted in 45.0 g (78%) of methyl 2,4-dibromobenzoate as a yellow oil. the mixture was concentrated under reduced pressure The residue was diluted with 500 mL of ethyl acetate washed with 3×100 mL of H2O The organic layer was dried over anhydrous sodium sulfate concentrated in vacuo This resulted in 45.0 g (78%) of methyl 2,4-dibromobenzoate as a yellow oil