methyl 5-bromo-2,4-dihydroxybenzoate

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 7.86 kg (83%) of methyl 5-bromo-2,4-dihydroxybenzoate and 9.65 kg of potassium carbonate are suspended in 100 l of acetonitrile at 0° C. The mixture is subsequently heated to 80° C., and 7575 ml of benzyl bromide are added via a dropping funnel over a period of 40 min. After stirring at 80° C. for 16 h, the mixture is filtered, and the collected filtrate is evaporated in vacuo: 12.95 kg (95%) of methyl 2,4-bisbenzyloxy-5-bromobenzoate (slightly yellow crystals); MW 427.3. the mixture is filtered the collected filtrate is evaporated in vacuo

反応条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 7.86 kg (83%) of methyl 5-bromo-2,4-dihydroxybenzoate and 9.65 kg of potassium carbonate are suspended in 100 l of acetonitrile at 0° C. The mixture is subsequently heated to 80° C., and 7575 ml of benzyl bromide are added via a dropping funnel over a period of 40 min. After stirring at 80° C. for 16 h, the mixture is filtered, and the collected filtrate is evaporated in vacuo: 12.95 kg (95%) of methyl 2,4-bisbenzyloxy-5-bromobenzoate (slightly yellow crystals); MW 427.3. the mixture is filtered the collected filtrate is evaporated in vacuo

反応条件: temp:55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 8.9 kg of 5-bromo-2,4-dihydroxybenzoic acid are dissolved in 70 l of methanol and heated to 55° C. 800 ml of sulfuric acid (w=95-98%) are subsequently metered in, and the mixture is stirred under gentle reflux for 4 days, with a further 500 ml of sulfuric acid (w=95-98%) being added daily (3 times). The reaction mixture is stirred into a cooled solution (5° C.) of 9 kg of sodium hydrogencarbonate in 100 l of water. Filtration and drying in vacuo at 50° C. gives 7.87 kg (83%) of methyl 5-bromo-2,4-dihydroxybenzoate (white crystals), MW 247.1. being added daily (3 times) Filtration drying in vacuo at 50° C.

反応条件: temp:55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 8.9 kg of 5-bromo-2,4-dihydroxybenzoic acid are dissolved in 70 l of methanol and heated to 55° C. 800 ml of sulfuric acid (w=95-98%) are subsequently metered in, and the mixture is stirred under gentle reflux for 4 days, with a further 500 ml of sulfuric acid (w=95-98%) being added daily (3 times). The reaction mixture is stirred into a cooled solution (5° C.) of 9 kg of sodium hydrogencarbonate in 100 l of water. Filtration and drying in vacuo at 50° C. gives 7.87 kg (83%) of methyl 5-bromo-2,4-dihydroxybenzoate (white crystals), MW 247.1. being added daily (3 times) Filtration drying in vacuo at 50° C.

反応条件: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of 5-Bromo-2,4-dihydroxy-benzoic acid methyl ester (1.0 g, 4.04 mmol) in DMF (7 mL) was added Cs2CO3 (1.58 g, 4.85 mmol) and benzylbromide (0.69 g, 4.04 mmol) and heated at 70° C. for 6 h. Reaction mixture was diluted with EtOAc (10 mL) and filtered, filtrate was washed with water, brine and dried over Na2SO4. Solvent was removed under reduced pressure and silicagel column chromatography (EtOAc:Hex, 1:3) gave pure 4-benzyloxy-5-bromo-2-hydroxy-benzoic acid methyl ester (0.62 g). Reaction mixture filtered filtrate was washed with water, brine dried over Na2SO4 Solvent was removed under reduced pressure and silicagel column chromatography (EtOAc:Hex, 1:3)

反応条件: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of 5-Bromo-2,4-dihydroxy-benzoic acid methyl ester (1.0 g, 4.04 mmol) in DMF (7 mL) was added Cs2CO3 (1.58 g, 4.85 mmol) and benzylbromide (0.69 g, 4.04 mmol) and heated at 70° C. for 6 h. Reaction mixture was diluted with EtOAc (10 mL) and filtered, filtrate was washed with water, brine and dried over Na2SO4. Solvent was removed under reduced pressure and silicagel column chromatography (EtOAc:Hex, 1:3) gave pure 4-benzyloxy-5-bromo-2-hydroxy-benzoic acid methyl ester (0.62 g). Reaction mixture filtered filtrate was washed with water, brine dried over Na2SO4 Solvent was removed under reduced pressure and silicagel column chromatography (EtOAc:Hex, 1:3)

反応条件: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of 5-Bromo-2,4-dihydroxy-benzoic acid methyl ester (1.0 g, 4.04 mmol) in DMF (7 mL) was added Cs2CO3 (1.58 g, 4.85 mmol) and benzylbromide (0.69 g, 4.04 mmol) and heated at 70° C. for 6 h. Reaction mixture was diluted with EtOAc (10 mL) and filtered, filtrate was washed with water, brine and dried over Na2SO4. Solvent was removed under reduced pressure and silicagel column chromatography (EtOAc:Hex, 1:3) gave pure 4-benzyloxy-5-bromo-2-hydroxy-benzoic acid methyl ester (0.62 g). Reaction mixture filtered filtrate was washed with water, brine dried over Na2SO4 Solvent was removed under reduced pressure and silicagel column chromatography (EtOAc:Hex, 1:3)

反応条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 7.86 kg of methyl 5-bromo-2,4-dihydroxybenzoate and 9.65 kg of potassium carbonate are suspended in 100 l of acetonitrile at 0° C. The mixture is subsequently heated to 80° C., and 7575 ml of benzyl bromide are added via a dropping funnel over a period of 40 min. After stirring overnight at 80° C., the mixture is filtered, and the collected filtrate is evaporated in vacuo: 12.95 kg (95%) of methyl 2,4-bisbenzyloxy-5-bromobenzoate (slightly yellow crystals); MW 427.3. the mixture is filtered the collected filtrate is evaporated in vacuo