甲基5-溴-2-羟基苯甲酸酯

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

实验步骤: To a mixture of methyl 5-bromo-2-hydroxybenzoate (150 g, 0.65 mol) in concentrated H2SO4 (320 mL) below 0° C. was added dropwise a mixture of concentrated HNO3 (69.2 g, 0.71 mol) and concentrated H2SO4 (97 mL) with stirring below 5° C. After the addition, the mixture was stirred at this temperature for 3 hr. The reaction mixture was poured into crash ice and the precipitate was collected, washed with cold water, hot ethanol and dried to give methyl 5-bromo-2-hydroxy-3-nitrobenzoate (153 g, yield 85%). 1H-NMR (400 MHz, CDCl3-d) δ 4.04 (s, 3H), 8.25 (d, J=2.4 Hz, 1H), 8.28 (d, J=2.4 Hz, 1H), 11.92 (s, 1H); LC-MS (ESI) m/z 278 [M+1]+. was added dropwise After the addition the mixture was stirred at this temperature for 3 hr The reaction mixture was poured into crash ice the precipitate was collected washed with cold water, hot ethanol dried

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

实验步骤: To a solution of methyl 2-hydroxybenzoate (152 g, 1.0 mol) in chloroform (500 mL) was added dropwise with stirring a solution of bromine (172 g, 1.08 mol) in chloroform (300 mL) at 10° C. After the addition, the solution was stirred at room temperature overnight. The mixture was diluted with dichloromethane (500 mL), washed with water (1 L×3), saturated sodium bicarbonate solution (500 mL), brine (500 mL), dried over anhydrous sodium sulfate and concentrated to give crude product. The crude product was re-crystallized from methanol to give methyl 5-bromo-2-hydroxybenzoate (192 g, yield 83%) as a white solid. 1H-NMR (400 MHz, CDCl3) δ 3.96 (s, 3H), 6.89 (d, J=8.8 Hz, 1H), 7.52-7.55 (dd, J=8.8 Hz, J=2 Hz, 1H), 7.96 (d, J=2.8 Hz, 1H), 10.7 (s, 1H); LC-MS (ESI) m/z 233 [M+1]+. After the addition washed with water (1 L×3), saturated sodium bicarbonate solution (500 mL), brine (500 mL) dried over anhydrous sodium sulfate concentrated to give crude product The crude product was re-crystallized from methanol

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

实验步骤: A mixture of 5-bromo-2-hydroxy-benzoic acid methyl ester (25.0 g, 103 mmol), 2-bromo-propionic acid ethyl ester (18.6 g, 103 mmol) and potassium carbonate (50.2 g, 360 mmol) in acetone (500 mL) is heated under reflux for 24 h. The reaction mixture is filtered, and the filtrate concentrated by rotary evaporation. The residue is dissolved in dichloromethane and washed twice with water. The organic layer is dried over Na2SO4, filtered and concentrated at reduced pressure to afford the title compound as a colorless oil (34.1 g, 103 mmol, 100%). 1H NMR (400 MHz, CDCl3, 298 K): δ=7.91 (d, J=2.7 Hz, 1H), 7.49 (dd, J=8.8, 2.7 Hz, 1H), 6.75 (d, J=8.8 Hz, 1H), 4.71 (q, J=6.8 Hz, 1H), 4.20 (q, J=7.1 Hz, 2H), 3.88 (s, 3H), 1.65 (d, J=6.8 Hz, 3H), 1.23 (t, J=7.1 Hz, 3H). MS (ES+): 331 (M(C13H1579BrO5)+H)+. is heated under reflux for 24 h The reaction mixture is filtered the filtrate concentrated by rotary evaporation The residue is dissolved in dichloromethane washed twice with water The organic layer is dried over Na2SO4 filtered concentrated at reduced pressure

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

实验步骤: To a solution of methyl 5-bromosalicylate (5.78 g, 25.00 mmol) in 30 mL of dry THF was added slowly sodium hydride (0.600 g, 25.00 mmol, 60 wt %) and the solution was stirred at rt for 15 minutes. The solvent was evaporated and the residue was dissolved in 10 mL of dry DMF. To this was added 3-bromo-4-nitropyridine 1-oxide (4.38 g, 20.00 mmol) and the reaction mixture was stirred at 50° C. for 4 h and 40° C. overnight. Water was added and the resulting solid was washed with water, filtered and dried under vacuum. Purification of the crude residue by column chromatography (CH2Cl2 to CH2Cl2/EA=10:1 to 5:1 to 3:1 to 1:1 to pure EA) gave 3-(4-bromo-2-(methoxycarbonyl)phenoxy)-4-nitropyridine 1-oxide as a yellow solid. The solvent was evaporated the residue was dissolved in 10 mL of dry DMF the reaction mixture was stirred at 50° C. for 4 h and 40° C. overnight the resulting solid was washed with water filtered dried under vacuum Purification of the crude residue by column chromatography (CH2Cl2 to CH2Cl2/EA=10:1 to 5:1 to 3:1 to 1:1 to pure EA)

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:; See reaction.notes.procedure_details.

实验步骤: To a mixture of 152 g (1.0 mole) of methyl salicylate and 500 ml of chloroform were added dropwise with stirring a solution of 172 g (1.08 mole) of bromine in 300 ml of chloroform at about 10° C. over a period of 6 hours. After the addition, the mixture was stirred at the same temperature for 1 hour. The reaction mixture was washed with water and then with an aqueous solution of sodium bicarbonate. Removal of the solvent gave 230 g of substantially pure methyl 5-bromosalicylate in 99.6% yield, M.P. 59° to 61.5° C. were added dropwise After the addition The reaction mixture was washed with water Removal of the solvent