dimethyl 3-hydroxybenzene-1,2-dicarboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: The starting material can be prepared as follows: 225 g of potassium carbonate and 98 g of allyl bromide are added to a solution of 170.0 g of dimethyl 3-hydroxy-phthalate in 400 ml of methyl ethyl ketone. The mixture is heated to the reflux temperature for 18 hours, whilst stirring, and then filtered, the filter residue is washed with methyl ethyl ketone and the filtrate, combined with the wash liquid, is evaporated under reduced pressure. The residual oily crude product is distilled under reduced pressure; dimethyl 3-allyloxyphthalate is obtained as the main fraction; boiling point 126°-130°/0.015 mm Hg. The starting material can be prepared The mixture is heated to the reflux temperature for 18 hours filtered the filter residue is washed with methyl ethyl ketone is evaporated under reduced pressure The residual oily crude product is distilled under reduced pressure

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

Procedure: Acetyl nitrate obtained by mixing acetic anhydride (3.6 g, 36 mmol) with fuming nitric acid (2.16 g, 36 mmol) at 0° C. was dropped into a solution of dimethyl 3-hydroxyphthalate (3.8 g, 18 mmol) in acetonitrile (60 ml) at 0° C. followed by stirring for 40 minutes. The reaction solution was diluted with water and extracted with ether. The organic layer was washed with water and a saturated sodium chloride solution successively and dried over anhydrous magnesium sulfate and the solvent was evaporated therefrom. A 3:2 mixture (4.34 g; yield 94%) of dimethyl 3-hydroxy-4-nitrophthalate and dimethyl 3-hydroxy-6-nitrophthalatewas obtained as a yellow solid. This was used in the next reaction without separation and purification. extracted with ether The organic layer was washed with water a saturated sodium chloride solution successively and dried over anhydrous magnesium sulfate the solvent was evaporated

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-Hydroxyphthalic anhydride (1.0 g, 6.6 mmol) was dissolved in methanol (20 ml), and a catalytic amount of p-toluene sulfonic acid was added to this solution. The mixture was stirred with refluxing under heating for 5 hours, and concentrated under reduced pressure to give a crude product of dimethyl 3-hydroxyphthalate. The crude product of dimethyl 3-hydroxyphthalate was dissolved in DMF (20 ml), and potassium carbonate (6 g, 43 mmol) and n-amyl bromide (3 ml, 24 mmol) were added to this solution. The mixture was stirred at 90° C. for 1.5 hours, and solids were removed by filtration through Celite. The filtrate was concentrated under reduced pressure to give a crude product of dimethyl 3-pentyloxyphthalate. The crude product of dimethyl 3-pentyloxyphthalate was dissolved in methanol (10 ml), and a 1N aqueous sodium hydroxide solution (20 ml) was added to this solution. The mixture was stirred at 90° C. for 2 hours, and a 3N aqueous hydrochloric acid solution (15 ml) was added to the reaction nixture. The mixture was extracted with ethyl acetate (30 ml×3), and washed with saturated brine (20 ml). The organic layer was dried over anhydrous magnesium sulfate. The drying agent was filtered off, and the filtrate was concentrated under reduced pressure to give a crude product of 3-pentyloxyphthalic acid. The crude product of 3-pentyloxyphthalic acid was dissolved in acetic acid (20 ml), and a mine hydrochloride (1.0 g, 7.3 mmol) was added. The mixture was stirred at 90° C. for 2 hours and concentrated under reduced pressure. The obtained residue was purified by column chromatography on silica gel (hexane/ethyl acetate=4/1) to give N-2-(4-hydroxyphenyl)ethyl-3-pentyloxyphthalimide (0.8 g, 2.3 mmol, 35%) as colorless crystals. solids were removed by filtration through Celite The filtrate was concentrated under reduced pressure

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-Hydroxyphthalic anhydride (1.0 g, 6.6 mmol) was dissolved in methanol (20 ml), and a catalytic amount of p-toluene sulfonic acid was added to this solution. The mixture was stirred with refluxing under heating for 5 hours, and concentrated under reduced pressure to give a crude product of dimethyl 3-hydroxyphthalate. The crude product of dimethyl 3-hydroxyphthalate was dissolved in DMF (20 ml), and potassium carbonate (6 g, 43 mmol) and n-amyl bromide (3 ml, 24 mmol) were added to this solution. The mixture was stirred at 90° C. for 1.5 hours, and solids were removed by filtration through Celite. The filtrate was concentrated under reduced pressure to give a crude product of dimethyl 3-pentyloxyphthalate. The crude product of dimethyl 3-pentyloxyphthalate was dissolved in methanol (10 ml), and a 1N aqueous sodium hydroxide solution (20 ml) was added to this solution. The mixture was stirred at 90° C. for 2 hours, and a 3N aqueous hydrochloric acid solution (15 ml) was added to the reaction nixture. The mixture was extracted with ethyl acetate (30 ml×3), and washed with saturated brine (20 ml). The organic layer was dried over anhydrous magnesium sulfate. The drying agent was filtered off, and the filtrate was concentrated under reduced pressure to give a crude product of 3-pentyloxyphthalic acid. The crude product of 3-pentyloxyphthalic acid was dissolved in acetic acid (20 ml), and a mine hydrochloride (1.0 g, 7.3 mmol) was added. The mixture was stirred at 90° C. for 2 hours and concentrated under reduced pressure. The obtained residue was purified by column chromatography on silica gel (hexane/ethyl acetate=4/1) to give N-2-(4-hydroxyphenyl)ethyl-3-pentyloxyphthalimide (0.8 g, 2.3 mmol, 35%) as colorless crystals. solids were removed by filtration through Celite The filtrate was concentrated under reduced pressure

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

Procedure: To a stirred suspension of 3-hydroxyphthalic acid dimethyl ester (1.1 g, 5.2 mmol) in acetone (45 mL) and potassium carbonate (2.2 g, 15.7 mmol), was added 1-bromomethyl-4-methoxy-benzene (0.79 mL, 5.5 mmol). The mixture was refluxed for six hours. The solvent was evaporated in vacuo, and the residue was partitioned between water (50 mL) and ethyl acetate (80 mL). The organic layer was washed with water (2×50 mL), dried, concentrated in vacuo, and purified by flash column chromatography (Silica Gel, EtOAc/Hexane, 0% gradient to 100% 30 min) to give 3-(4-methoxy-benzyloxy)-phthalic acid dimethyl ester (2.0 g, 115% crude yield). The product was used in the next step without further purification. The mixture was refluxed for six hours The solvent was evaporated in vacuo the residue was partitioned between water (50 mL) and ethyl acetate (80 mL) The organic layer was washed with water (2×50 mL) dried concentrated in vacuo purified by flash column chromatography (Silica Gel, EtOAc/Hexane, 0% gradient to 100% 30 min)

Conditions: temp:55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A stirred mixture of 3-hydroxyphthalic anhydride (20.5 g, 125 mmol) in methanol (100 mL) was heated to reflux for three hours. The solvent was evaporated in vacuo, and the residue was suspended in sodium bicarbonate (29.4 g, 350 mmol) in DMF (250 mL), followed by addition of iodomethane (19 mL, 300 mmol) and heating at 55° C. for four hours. The mixture was cooled to room temperature, solvent evaporated in vacuo, and the residue was partitioned between water (200 mL) and ethyl acetate (200 mL). The organic layer was washed with water (2×200 mL), dried, concentrated in vauco, and then purified by flash column chromatography (Silica Gel, EtOAc/Hexane, 0% gradient to 100% 30 min) to give 3-hydroxyphthalic acid dimethyl ester (20.2 g, 77% yield). The product was used in the next step without further purification. was heated to reflux for three hours The solvent was evaporated in vacuo The mixture was cooled to room temperature solvent evaporated in vacuo the residue was partitioned between water (200 mL) and ethyl acetate (200 mL) The organic layer was washed with water (2×200 mL) dried concentrated in vauco purified by flash column chromatography (Silica Gel, EtOAc/Hexane, 0% gradient to 100% 30 min)

Conditions: temp:55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A stirred mixture of 3-hydroxyphthalic anhydride (20.5 g, 125 mmol) in methanol (100 mL) was heated to reflux for three hours. The solvent was evaporated in vacuo, and the residue was suspended in sodium bicarbonate (29.4 g, 350 mmol) in DMF (250 mL), followed by addition of iodomethane (19 mL, 300 mmol) and heating at 55° C. for four hours. The mixture was cooled to room temperature, solvent evaporated in vacuo, and the residue was partitioned between water (200 mL) and ethyl acetate (200 mL). The organic layer was washed with water (2×200 mL), dried, concentrated in vauco, and then purified by flash column chromatography (Silica Gel, EtOAc/Hexane, 0% gradient to 100% 30 min) to give 3-hydroxyphthalic acid dimethyl ester (20.2 g, 77% yield). The product was used in the next step without further purification. was heated to reflux for three hours The solvent was evaporated in vacuo The mixture was cooled to room temperature solvent evaporated in vacuo the residue was partitioned between water (200 mL) and ethyl acetate (200 mL) The organic layer was washed with water (2×200 mL) dried concentrated in vauco purified by flash column chromatography (Silica Gel, EtOAc/Hexane, 0% gradient to 100% 30 min)