5-bromo-2-methyl-2,3-dihydro-1-benzofuran

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

Procedure: 470 g (4.03 moles) of chlorosulfonic acid are added dropwise over 20 minutes at -7° C. to a solution of 106 g (0.5 mole) of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan in 300 ml of chloroform, and the mixture is then stirred for a further 15 minutes at 20°-25° C. The reaction mixture is taken up in ice/water, the organic phase is separated, and aqueous phase is extracted with two 500 ml portions of chloroform. The combined organic phases are washed with two 250 ml portions of water, dried over sodium sulfate, and concentrated, affording 101 g (65% of theory) of 5-bromo-2,3-dihydro-2-methyl-7-benzo[b]furanylsulfochloride. the organic phase is separated aqueous phase is extracted with two 500 ml portions of chloroform The combined organic phases are washed with two 250 ml portions of water dried over sodium sulfate concentrated

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

Procedure: With efficient stirring, 283 g. (1.77 moles) of bromine are added dropwise at 0°-5° C. to a mixture of 237 g (1.77 moles) of 2,3-dihydro-2-methylbenzo[b]furan, 148.7 g (1.77 moles) of sodium bicarbonate, 500 ml of methylene chloride and 500 ml of water. When the addition of bromine is complete, the mixture is stirred for another 1/2 hour at 20°-25° C. The organic phase is separated, dried over sodium sulfate, concentrated and fractionated in vacuo. Yield: 242 g (66% of theory) of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan and 77 g (15% theory) of 5,7-dibromo-2,3-dihydro-2-methylbenzo[b]furan. The organic phase is separated dried over sodium sulfate concentrated

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

Procedure: A solution of 215 ml of bromine in 450 ml of methylene chloride is added dropwise over 21/2 hours to an ice-cooled mixture of 562.3 g of 2,3-dihydro-2-methylbenzo[b]furan, 1600 ml of methylene chloride, 1600 ml of water and 352.5 g of sodium bicarbonate. After the mixture has been stirred for another 11/2 hours at the same temperature, the aqueous phase is separated and extracted with two 300 ml portions of methylene chloride. The combined organic phases are washed with 2×250 ml of water, dried over sodium sulfate and concentrated. After removal of all constituents having a boiling point below 99° C. under a pressure of 8 mbar, there are obtained 750.7 g of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan as residue. cooled the aqueous phase is separated extracted with two 300 ml portions of methylene chloride The combined organic phases are washed with 2×250 ml of water dried over sodium sulfate concentrated After removal of all constituents

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

Procedure: A solution of 215 ml of bromine in 450 ml of methylene chloride is added dropwise over 21/2 hours to an ice-cooled mixture of 562.3 g of 2,3-dihydro-2-methylbenzo[b]furan, 1600 ml of methylene chloride, 1600 ml of water and 352.5 g of sodium bicarbonate. After the mixture has been stirred for another 11/2 hours at the same temperature, the aqueous phase is separated and extracted with two 300 ml portions of methylene chloride. The combined organic phases are washed with 2×250 ml of water, dried over sodium sulfate and concentrated. After removal of all constituents having a boiling point below 99° C. under a pressure of 8 mbar, there are obtained 750.7 g of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan as residue. cooled the aqueous phase is separated extracted with two 300 ml portions of methylene chloride The combined organic phases are washed with 2×250 ml of water dried over sodium sulfate concentrated After removal of all constituents

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

Procedure: A mixture of 5-bromo-2-methyl-2,3-dihydro-1-benzofuran (1.0 g, 4.72 mmol), CH3SO2Na (730 mg, 7.08 mmol), L-proline (110 mg, 0.94 mmol), K2CO3 (120 mg, 0.94 mmol) and CuI (89 mg, 0.47 mmol) in DMSO (10 mL) was irradiated at 140° C. for 2 h under microwave. The mixture was extracted with EtOAc (2×30 mL). The combined organic layers were washed with brine (30 mL), dried over Na2SO4, filtered and concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1) to give the title compound (500 mg, 50%). 1H NMR (CDCl3, 400 MHz) δ 7.71-7.70 (m, 2H), 6.86-6.82 (m, 1H), 5.08-5.03 (m, 1H), 3.41-3.35 (m, 1H), 3.02 (s, 3H), 2.89-2.83 (m, 1H), 1.56 (d, J=6.4 Hz, 3H). was irradiated at 140° C. for 2 h under microwave The mixture was extracted with EtOAc (2×30 mL) The combined organic layers were washed with brine (30 mL) dried over Na2SO4 filtered concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1)

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

Procedure: A mixture of 5-bromo-2-methyl-2,3-dihydro-1-benzofuran (1.0 g, 4.72 mmol), CH3SO2Na (730 mg, 7.08 mmol), L-proline (110 mg, 0.94 mmol), K2CO3 (120 mg, 0.94 mmol) and CuI (89 mg, 0.47 mmol) in DMSO (10 mL) was irradiated at 140° C. for 2 h under microwave. The mixture was extracted with EtOAc (2×30 mL). The combined organic layers were washed with brine (30 mL), dried over Na2SO4, filtered and concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1) to give the title compound (500 mg, 50%). 1H NMR (CDCl3, 400 MHz) δ 7.71-7.70 (m, 2H), 6.86-6.82 (m, 1H), 5.08-5.03 (m, 1H), 3.41-3.35 (m, 1H), 3.02 (s, 3H), 2.89-2.83 (m, 1H), 1.56 (d, J=6.4 Hz, 3H). was irradiated at 140° C. for 2 h under microwave The mixture was extracted with EtOAc (2×30 mL) The combined organic layers were washed with brine (30 mL) dried over Na2SO4 filtered concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1)

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

Procedure: 470 g (4.03 moles) of chlorosulfonic acid are added dropwise over 20 minutes at -7° C. to a solution of 106 g (0.5 mole) of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan in 300 ml of chloroform, and the mixture is then stirred for a further 15 minutes at 20°-25° C. The reaction mixture is taken up in ice/water, the organic phase is separated, and aqueous phase is extracted with two 500 ml portions of chloroform. The combined organic phases are washed with two 250 ml portions of water, dried over sodium sulfate, and concentrated, affording 101 g (65% of theory) of 5-bromo-2,3-dihydro-2-methyl-7-benzo[b]furanylsulfochloride. the organic phase is separated aqueous phase is extracted with two 500 ml portions of chloroform The combined organic phases are washed with two 250 ml portions of water dried over sodium sulfate concentrated

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

Procedure: With efficient stirring, 283 g. (1.77 moles) of bromine are added dropwise at 0°-5° C. to a mixture of 237 g (1.77 moles) of 2,3-dihydro-2-methylbenzo[b]furan, 148.7 g (1.77 moles) of sodium bicarbonate, 500 ml of methylene chloride and 500 ml of water. When the addition of bromine is complete, the mixture is stirred for another 1/2 hour at 20°-25° C. The organic phase is separated, dried over sodium sulfate, concentrated and fractionated in vacuo. Yield: 242 g (66% of theory) of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan and 77 g (15% theory) of 5,7-dibromo-2,3-dihydro-2-methylbenzo[b]furan. The organic phase is separated dried over sodium sulfate concentrated

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

Procedure: A solution of 215 ml of bromine in 450 ml of methylene chloride is added dropwise over 21/2 hours to an ice-cooled mixture of 562.3 g of 2,3-dihydro-2-methylbenzo[b]furan, 1600 ml of methylene chloride, 1600 ml of water and 352.5 g of sodium bicarbonate. After the mixture has been stirred for another 11/2 hours at the same temperature, the aqueous phase is separated and extracted with two 300 ml portions of methylene chloride. The combined organic phases are washed with 2×250 ml of water, dried over sodium sulfate and concentrated. After removal of all constituents having a boiling point below 99° C. under a pressure of 8 mbar, there are obtained 750.7 g of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan as residue. cooled the aqueous phase is separated extracted with two 300 ml portions of methylene chloride The combined organic phases are washed with 2×250 ml of water dried over sodium sulfate concentrated After removal of all constituents

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

Procedure: A solution of 215 ml of bromine in 450 ml of methylene chloride is added dropwise over 21/2 hours to an ice-cooled mixture of 562.3 g of 2,3-dihydro-2-methylbenzo[b]furan, 1600 ml of methylene chloride, 1600 ml of water and 352.5 g of sodium bicarbonate. After the mixture has been stirred for another 11/2 hours at the same temperature, the aqueous phase is separated and extracted with two 300 ml portions of methylene chloride. The combined organic phases are washed with 2×250 ml of water, dried over sodium sulfate and concentrated. After removal of all constituents having a boiling point below 99° C. under a pressure of 8 mbar, there are obtained 750.7 g of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan as residue. cooled the aqueous phase is separated extracted with two 300 ml portions of methylene chloride The combined organic phases are washed with 2×250 ml of water dried over sodium sulfate concentrated After removal of all constituents

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

Procedure: A mixture of 5-bromo-2-methyl-2,3-dihydro-1-benzofuran (1.0 g, 4.72 mmol), CH3SO2Na (730 mg, 7.08 mmol), L-proline (110 mg, 0.94 mmol), K2CO3 (120 mg, 0.94 mmol) and CuI (89 mg, 0.47 mmol) in DMSO (10 mL) was irradiated at 140° C. for 2 h under microwave. The mixture was extracted with EtOAc (2×30 mL). The combined organic layers were washed with brine (30 mL), dried over Na2SO4, filtered and concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1) to give the title compound (500 mg, 50%). 1H NMR (CDCl3, 400 MHz) δ 7.71-7.70 (m, 2H), 6.86-6.82 (m, 1H), 5.08-5.03 (m, 1H), 3.41-3.35 (m, 1H), 3.02 (s, 3H), 2.89-2.83 (m, 1H), 1.56 (d, J=6.4 Hz, 3H). was irradiated at 140° C. for 2 h under microwave The mixture was extracted with EtOAc (2×30 mL) The combined organic layers were washed with brine (30 mL) dried over Na2SO4 filtered concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1)

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

Procedure: A mixture of 5-bromo-2-methyl-2,3-dihydro-1-benzofuran (1.0 g, 4.72 mmol), CH3SO2Na (730 mg, 7.08 mmol), L-proline (110 mg, 0.94 mmol), K2CO3 (120 mg, 0.94 mmol) and CuI (89 mg, 0.47 mmol) in DMSO (10 mL) was irradiated at 140° C. for 2 h under microwave. The mixture was extracted with EtOAc (2×30 mL). The combined organic layers were washed with brine (30 mL), dried over Na2SO4, filtered and concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1) to give the title compound (500 mg, 50%). 1H NMR (CDCl3, 400 MHz) δ 7.71-7.70 (m, 2H), 6.86-6.82 (m, 1H), 5.08-5.03 (m, 1H), 3.41-3.35 (m, 1H), 3.02 (s, 3H), 2.89-2.83 (m, 1H), 1.56 (d, J=6.4 Hz, 3H). was irradiated at 140° C. for 2 h under microwave The mixture was extracted with EtOAc (2×30 mL) The combined organic layers were washed with brine (30 mL) dried over Na2SO4 filtered concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1)