ethyl 5-bromo-1-benzofuran-3-carboxylate

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of ethyl 5-bromobenzofuran-3-carboxylate (95 g, 353 mmol) in CHCl3 (1000 mL), fuming HNO3 (192 mL, 95%) was added dropwise at −20° C. over 90 min and stirred at 0° C. for 1 hour. The reaction mixture was added to ice water and extracted with CH2Cl2. The organic layer was washed with NaHCO3 and brine. The solvent was removed by distillation to provide the crude product of ethyl 5-bromo-6-nitrobenzofuran-3-carboxylate (95 g, yield: 85%). It was used for the next step without further purification. extracted with CH2Cl2 The organic layer was washed with NaHCO3 and brine The solvent was removed by distillation

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

実験手順: Et2O (16.2 g, 99.5 mmol) was added to a solution of 5-bromo-2-hydroxybenzaldehyde (200 g, 995 mmol) in CH2Cl2 (500 mL), and then a solution of ethyl diazoacetate (180 g, 1.42 mol) in CH2Cl2 (500 mL) was introduced as evolution of N2 gas while the reaction was not allowed over 38° C. Once gas evolution ceased, the reaction mixture was concentrated by rotary evaporator and conc. H2SO4 (129 g, 1.29 mol, 98%) was added to the mixture while stirring. After 20 minutes, the acidic mixture was neutralized with Na2CO3 (a.q). After the mixture was stored and crystallized overnight, ethyl 5-bromobenzofuran-3-carboxylate (100 g, yield: 75%) was obtained by filtration. 1H-NMR (CDCl3, 400 MHz) δ 8.25 (s, 1H), 8.15˜8.21 (m, 1H), 7.44˜7.50 (m, 1H), 7.37˜7.42 (m, 1H), 4.41 (q, J=7.2 Hz, 2H), 1.43 (t, J=7.2 Hz, 3H). MS (M+H)+: 269/271. was not allowed over 38° C was added to the mixture crystallized overnight

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of ethyl 5-bromobenzofuran-3-carboxylate (95 g, 353 mmol) in CHCl3 (1000 mL), fuming HNO3 (192 mL, 95%) was added dropwise at −20° C. over 90 min and stirred at 0° C. for 1 hour. The reaction mixture was added to ice water and extracted with CH2Cl2. The organic layer was washed with NaHCO3 and brine. The solvent was removed by distillation to provide the crude product of ethyl 5-bromo-6-nitrobenzofuran-3-carboxylate (95 g, yield: 85%). It was used for the next step without further purification. extracted with CH2Cl2 The organic layer was washed with NaHCO3 and brine The solvent was removed by distillation

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

実験手順: Et2O (16.2 g, 99.5 mmol) was added to a solution of 5-bromo-2-hydroxybenzaldehyde (200 g, 995 mmol) in CH2Cl2 (500 mL), and then a solution of ethyl diazoacetate (180 g, 1.42 mol) in CH2Cl2 (500 mL) was introduced as evolution of N2 gas while the reaction was not allowed over 38° C. Once gas evolution ceased, the reaction mixture was concentrated by rotary evaporator and conc. H2SO4 (129 g, 1.29 mol, 98%) was added to the mixture while stirring. After 20 minutes, the acidic mixture was neutralized with Na2CO3 (a.q.). After the mixture was stored and crystallized overnight, ethyl 5-bromobenzofuran-3-carboxylate (100 g, yield: 75%) was obtained by filtration. 1H-NMR (400 MHz, CDCl3) δ 8.25 (s, 1H), 8.15˜8.21 (m, 1H), 7.44˜7.50 (m, 1H), 7.37˜7.42 (m, 1H), 4.41 (q, J=7.2 Hz, 2H), 1.43 (t, J=7.2 Hz, 3H). was not allowed over 38° C was added to the mixture crystallized overnight

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

実験手順: Et2O (16.2 g, 99.5 mmol) was added to a solution of 5-bromo-2-hydroxybenzaldehyde (200 g, 995 mmol) in CH2Cl2 (500 mL), and then a solution of ethyl diazoacetate (180 g, 1.42 mol) in CH2Cl2 (500 mL) was introduced as evolution of N2 gas while the reaction was not allowed over 38° C. Once gas evolution ceased, the reaction mixture was concentrated by rotary evaporator and conc. H2SO4 (129 g, 1.29 mol, 98%) was added to the mixture while stirring. After 20 minutes, the acidic mixture was neutralized with Na2CO3 (a.q.). After the mixture was stored and crystallized overnight, ethyl 5-bromobenzofuran-3-carboxylate (100 g, yield: 75%) was obtained by filtration. 1H-NMR (400 MHz, CDCl3) δ 8.25 (s, 1H), 8.15˜8.21 (m, 1H), 7.44˜7.50 (m, 1H), 7.37˜7.42 (m, 1H), 4.41 (q, J=7.2 Hz, 2H), 1.43 (t, J=7.2 Hz, 3H). was not allowed over 38° C was added to the mixture crystallized overnight

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of ethyl 5-bromobenzofuran-3-carboxylate (95 g, 353 mmol) in CHCl3 (1000 mL), fuming HNO3 (192 mL, 95%) was added dropwise at −20° C. over 90 min and stirred at 0° C. for 1 hour. The reaction mixture was added to ice water and extracted with CH2Cl2. The organic layer was washed with NaHCO3 and brine. The solvent was removed by distillation to provide the crude product of ethyl 5-bromo-6-nitrobenzofuran-3-carboxylate (95 g, yield: 85%). It was used for the next step without further purification. extracted with CH2Cl2 The organic layer was washed with NaHCO3 and brine The solvent was removed by distillation

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

実験手順: Et2O (16.2 g, 99.5 mmol) was added to a solution of 5-bromo-2-hydroxybenzaldehyde (200 g, 995 mmol) in CH2Cl2 (500 mL), and then a solution of ethyl diazoacetate (180 g, 1.42 mol) in CH2Cl2 (500 mL) was introduced as evolution of N2 gas while the reaction was not allowed over 38° C. Once gas evolution ceased, the reaction mixture was concentrated by rotary evaporator and conc. H2SO4 (129 g, 1.29 mol, 98%) was added to the mixture while stirring. After 20 minutes, the acidic mixture was neutralized with Na2CO3 (a.q). After the mixture was stored and crystallized overnight, ethyl 5-bromobenzofuran-3-carboxylate (100 g, yield: 75%) was obtained by filtration. 1H-NMR (CDCl3, 400 MHz) δ 8.25 (s, 1H), 8.15˜8.21 (m, 1H), 7.44˜7.50 (m, 1H), 7.37˜7.42 (m, 1H), 4.41 (q, J=7.2 Hz, 2H), 1.43 (t, J=7.2 Hz, 3H). MS (M+H)+: 269/271. was not allowed over 38° C was added to the mixture crystallized overnight

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of ethyl 5-bromobenzofuran-3-carboxylate (95 g, 353 mmol) in CHCl3 (1000 mL), fuming HNO3 (192 mL, 95%) was added dropwise at −20° C. over 90 min and stirred at 0° C. for 1 hour. The reaction mixture was added to ice water and extracted with CH2Cl2. The organic layer was washed with NaHCO3 and brine. The solvent was removed by distillation to provide the crude product of ethyl 5-bromo-6-nitrobenzofuran-3-carboxylate (95 g, yield: 85%). It was used for the next step without further purification. extracted with CH2Cl2 The organic layer was washed with NaHCO3 and brine The solvent was removed by distillation

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

実験手順: Et2O (16.2 g, 99.5 mmol) was added to a solution of 5-bromo-2-hydroxybenzaldehyde (200 g, 995 mmol) in CH2Cl2 (500 mL), and then a solution of ethyl diazoacetate (180 g, 1.42 mol) in CH2Cl2 (500 mL) was introduced as evolution of N2 gas while the reaction was not allowed over 38° C. Once gas evolution ceased, the reaction mixture was concentrated by rotary evaporator and conc. H2SO4 (129 g, 1.29 mol, 98%) was added to the mixture while stirring. After 20 minutes, the acidic mixture was neutralized with Na2CO3 (a.q.). After the mixture was stored and crystallized overnight, ethyl 5-bromobenzofuran-3-carboxylate (100 g, yield: 75%) was obtained by filtration. 1H-NMR (400 MHz, CDCl3) δ 8.25 (s, 1H), 8.15˜8.21 (m, 1H), 7.44˜7.50 (m, 1H), 7.37˜7.42 (m, 1H), 4.41 (q, J=7.2 Hz, 2H), 1.43 (t, J=7.2 Hz, 3H). was not allowed over 38° C was added to the mixture crystallized overnight