2-氨基-4-溴酚

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of 12 g of methanesulfonic acid and 1.8 g of phosphorus pentoxide (P2O5) was stirred 12 hours. To this well stirred suspension was added 0.346 g (4.8 mmol) of acrylic acid and 0.808 g (4 mmol) of 2-amino-4-bromo-phenol. The reaction was heated at 78° C. for 5 hours, then cooled to room temperature. The reaction was then slowly poured into a well-stirred slurry of 15 mL of 50% aqueous NaOH in 200 g of ice and water. The mixture was then poured into a separatory funnel and shaken with 300 mL water, 200 mL of diethyl ether, and 75 mL of dichloromethane and shaken vigorously. A small quantity of solid was removed by suction filtration, and the filtrate again shaken vigorously in a separatory funnel. The organic phase was collected, dried over Na2SO4, and concentrated in vacuo to a thick syrup that crystallized to give large yellow stars. Purification by flash chromatography on silica gel (eluting with 1:1 hexane:dichloromethane) gave 0.404 g (45%) of 5-bromo-2-vinyl-benzooxazole as a white powder, mp 55-56° C. 1H NMR (300 MHz, CDCl3) δ 7.84 (d, J=1.8 Hz, 1 H), 7.46 (dd, J=8.7, 1.8 Hz, 1 H), 7.40 (d, J=8.7 Hz, 1 H), 6.76 (dd, J=17, 10.5 Hz, 1 H), 6.50 (d, J=17 Hz, 1 H), 5.90 (d, J=10.5 Hz, 1 H); Mass spectrum: [M+H]+ at 224.0 & 226.0. To this well stirred suspension cooled to room temperature The mixture was then poured into a separatory funnel shaken vigorously A small quantity of solid was removed by suction filtration the filtrate again shaken vigorously in a separatory funnel The organic phase was collected dried over Na2SO4 concentrated in vacuo to a thick syrup that crystallized to give large yellow stars Purification by flash chromatography on silica gel (eluting with 1:1 hexane:dichloromethane)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Triethylamine (2.4 mL, 17 mmol) was added to 2-amino-4-bromophenol (2.5 g, 13 mmol) in THF (80 mL). The reaction was cooled in ice and chloroacetyl chloride (1.12 mL, 14 mmol) added portionwise. It was stirred with cooling for 10 min then allowed to warm to r.t. and stirred for a further 2 h. The reaction mixture was cooled in ice and sodium hydride (1.05 g of a 60% suspension in oil, 26 mmol) was added portionwise. The mixture was stirred with ice-bath cooling for 20 min then at r.t. for 2 h before being quenched with water (20 mL). The THF was removed in vacuo and the resulting mixture diluted with water (100 mL). The precipitate was filtered off, washed with water (3×50 mL) and dried in vacuo to yield the title compound as a beige solid (2.14 g, 70%). δH (DMSO-d6) 4.60 (2H, s), 6.92 (1H, d, J 8.5 Hz), 7.02 (1H, d, J 2.3 Hz), 7.08 (1H, dd, J 8.5, 2.3 Hz), 10.81 (1H, br s). The reaction was cooled in ice with cooling for 10 min stirred for a further 2 h The reaction mixture was cooled in ice The mixture was stirred with ice-bath cooling for 20 min at r.t. for 2 h before being quenched with water (20 mL) The THF was removed in vacuo the resulting mixture diluted with water (100 mL) The precipitate was filtered off washed with water (3×50 mL) dried in vacuo

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Potassium ethyl xanthate (416 mg, 2.60 mmol) was added to a solution of 2-amino-4-bromophenol (244 mg, 1.30 mmol) in EtOH (3.24 mL). The reaction mixture was heated at reflux for 4 h. Upon cooling to RT the mixture was concentrated and the resulting residue was dissolved in water. Acetic acid was added until pH=5 and a white solid precipitated from the solution. The solid was filtered, washed with water and dried to afford 270 mg (90%) of a tan powder which was used without further purification: 1H NMR (d6-DMSO, 400 MHz) δ 14.02 (s, 1H), 7.47-7.38 (m, 3H); 13C (d6-DMSO, 400 MHz) δ 181.4, 148.1, 133.7, 127.1, 117.8, 118.8, 112.2; MS (Cl) m/z 229.8 (M−1); HPLC retention time=4.34 min. The reaction mixture was heated at reflux for 4 h was concentrated the resulting residue was dissolved in water Acetic acid was added until pH=5 a white solid precipitated from the solution The solid was filtered washed with water dried

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of KOH (5.14 g, 91.7 mmol) in water (33 mL) was added to 4-bromo-2-nitrophenol (Aldrich, 1.00 g, 4.59 mmol). Sodium hydrosulfite (7.98 g, 45.9 mmol) was added in one portion. The mixture was stirred at RT for 30 min. and poured into ethyl acetate (25 mL). The layers were partitioned and the aqueous layer was extracted with ethyl acetate (4×25 mL). The combined organic layers were dried (Na2SO4), filtered and concentrated to give 488 mg (56%) of the title compound which was used without further purification: 1H NMR (CDCl3, 400 MHz) δ 6.77 (d, 1H, J=2.1 Hz), 6.65 (dd, 1H, J=8.3, 2.5 Hz), 6.52 (d, 1H, J=8.3 Hz); 13C NMR (CDCl3, 100 MHz) δ 144.0, 136.6, 121.7, 118.7, 116.2, 112.1; MS (Cl) m/z 188.0 (M+1); HPLC retention time=1.10 min. The layers were partitioned the aqueous layer was extracted with ethyl acetate (4×25 mL) The combined organic layers were dried (Na2SO4) filtered concentrated

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of the product 2-amino-4-bromophenol (500 mg, 2.66 mmol), 1,2-dibromoethane (2.5 g, 13.3 mmol) and K2CO3 (1.84 g, 13.3 mmol) in DMF (10 mL) was stirred at room temperature for 4 h. The mixture was diluted with water (100 mL) and extracted with ethyl acetate (100 mL). The organic layer was washed with water (3×50 mL) and brine (50 mL), concentrated and purified by column chromatography on silica gel (ethyl acetate in petroleum, 10% v/v) to give 5-bromo-2-(2-bromoethoxy)benzenamine (250 mg, 37%) as a yellow solid. LCMS: 294 [M+1]+. 1H NMR (400 MHz, DMSO-d6) δ 3.79 (t, J=6.0 Hz, 2H), 4.25 (t, J=5.6 Hz, 2H), 5.06 (s, 2H), 6.63 (dd, J1=2.4 Hz, J2=8.0 Hz, 1H), 6.77 (d, J=8.4 Hz, 1H), 6.82 (d, J=2.4 Hz, 1H). extracted with ethyl acetate (100 mL) The organic layer was washed with water (3×50 mL) and brine (50 mL) concentrated purified by column chromatography on silica gel (ethyl acetate in petroleum, 10% v/v)

反应条件: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of compound 4-bromo-2-nitrophenol (1 g, 4.59 mmol) and SnCl2 (5.2 g, 22.9 mmol) in ethanol (10 mL) was stirred at 70° C. for 2 h. After cooled down, the mixture was diluted with water (100 mL), adjusted to pH 7 with saturated aqueous NaHCO3 and extracted with ethyl acetate (100 mL). The organic layer was washed with brine (50 mL), dried over Na2SO4, concentrated to give 2-amino-4-bromophenol (770 mg, 89%) as a grey solid. LCMS: 188 [M+1]+. 1H NMR (400 MHz, DMSO-d6) δ 4.79 (s, 2H), 6.48 (dd, J1=2.4 Hz, J2=8.4 Hz, 1H), 6.55 (d, J=8.4 Hz, 1H), 6.71 (d, J=2.4 Hz, 1H), 9.26 (s, 1H). After cooled down extracted with ethyl acetate (100 mL) The organic layer was washed with brine (50 mL) dried over Na2SO4 concentrated

反应条件: temp:0.00; pressure:0.00; stir: