3-bromo-2-methyl-1-benzofuran

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl benzofuran-5-carboxylate (1.74 g, 9.9 mmol) is dissolved in CH2Cl2 (50 mL), layered with saturated NaHCO3 (75 mL) using very slow magnetic stirring so that the two layers are not mixed and treated with Br2 (3.1 mL, 59.1 mmol). The bi-phasic mixture is stirred slowly for 2 h, then vigorously for 1 h. The layers are separated and the aqueous layer is extracted with CH2Cl2 (2×50 mL). The organics are dried (Na2SO4) and concentrated under reduced pressure without heat. The residue is dissolved in MeOH (100 mL), treated with K2CO3 (8.17 g, 59.1 mmol) and stirred at RT for 18 h. The mixture is concentrated to dryness, partitioned between 50% saturated NaHCO3 (75 mL) and EtOAc (2×75 mL) and the organics are dried (Na2SO4) and concentrated in vacuo. The crude material (2.21 g) is adsorbed onto silica gel (4.5 g) chromatographed over 90 g slurry-packed silica gel, eluting with 8% EtOAc/hexane then 15% EtOAc/hexane. The appropriate fractions are combined and concentrated to afford 1.88 g (75%) of methyl 3-bromo-1-benzofuran as a white solid. 1H NMR (300 MHz, CDCl3): δ 3.99, 7.55, 7.74, 8.11, 8.31 ppm. are not mixed The bi-phasic mixture is stirred slowly for 2 h The layers are separated the aqueous layer is extracted with CH2Cl2 (2×50 mL) The organics are dried (Na2SO4) concentrated under reduced pressure without heat The residue is dissolved in MeOH (100 mL) stirred at RT for 18 h The mixture is concentrated to dryness partitioned between 50% saturated NaHCO3 (75 mL) and EtOAc (2×75 mL) the organics are dried (Na2SO4) concentrated in vacuo chromatographed over 90 g slurry-packed silica gel eluting with 8% EtOAc/hexane concentrated

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2.7 g (15.3 mmoles) of N-bromosuccinimide and 0.4 g (2.7 mmoles) of azobisisobutyronitrile were added to a solution of 2.8 g (13.3 mmoles) of 3-bromo-2-mehtylbenzofuran dissolved in 30 ml of monochlorobenzene. The mixture was stirred at 80° C. for 30 minutes to give rise to a reaction. After confirmation of the disappearance of the raw materials, the reaction mixture was cooled to room temperature. The insolubles were removed by filtration. The filtrate was subjected to vacuum distillation to remove the solvent contained therein. The residue was poured into water, followed by extraction with ethyl acetate. The resulting organic layer was washed with water and an aqueous sodium chloride solution in this order and then dried over anhydrous magnesium sulfate. The resulting solution was subjected to vacuum distillation to remove the solvent contained therein, to obtain 3.0 g (yield: 79.0%) of 3-bromo-2-bromomethylbenzofuran. to give rise to a reaction The insolubles were removed by filtration The filtrate was subjected to vacuum distillation to remove the solvent The residue was poured into water followed by extraction with ethyl acetate The resulting organic layer was washed with water an aqueous sodium chloride solution in this order and then dried over anhydrous magnesium sulfate The resulting solution was subjected to vacuum distillation to remove the solvent

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2.7 g (15.3 mmoles) of N-bromosuccinimide and 0.4 g (2.7 mmoles) of azobisisobutyronitrile were added to a solution of 2.8 g (13.3 mmoles) of 3-bromo-2-methylbenzofuran dissolved in 30 ml of monochlorobenzene. The mixture was stirred at 80° C. for 30 minutes to give rise to a reaction. After confirmation of the disappearance of the raw materials, the reaction mixture was cooled to room temperature. The insolubles were removed by filtration. The filtrate was subjected to vacuum distillation to remove the solvent contained therein. The residue was poured into water, followed by extraction with ethyl acetate. The resulting organic layer was washed with water and an aqueous sodium chloride solution in this order and then dried over anhydrous magnesium sulfate. The resulting solution was subjected to vacuum distillation to remove the solvent contained therein, to obtain 3.0 g (yield: 79.0%) of 3-bromo-2-bromomethylbenzofuran. to give rise to a reaction The insolubles were removed by filtration The filtrate was subjected to vacuum distillation to remove the solvent The residue was poured into water followed by extraction with ethyl acetate The resulting organic layer was washed with water an aqueous sodium chloride solution in this order and then dried over anhydrous magnesium sulfate The resulting solution was subjected to vacuum distillation to remove the solvent

Conditions: temp:0.00; pressure:0.00; stir: