ethyl 2,5-dihydroxybenzoate

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

Procedure: In the solution of 220 g(2 mol) of hydroquinone in 500 ml of acetic acid, 108.5 g(1 mol) of ethyl chloroformate was drop-added for one hour while agitating the solution at 110° C. The mixture was maintained at 110° C. for two hours, and acetic acid was distilled under vacuum. 1 liter of methylene chloride was added to the reaction mixture, and the unreacted excess hydroquinone was filtered and collected (recoverd amount: 110 g, recycled without any purification process). A desired mono ethoxycarbonyl hydroquinone was obtained by evaporating the residue under vacuum. (Yield: 164.6 g(98%). mp: 81-82° C., 1H-NMR(200 MHz, CDCl3, ppm) 1.38 (t, 3H), 4.31 (q, 2H), 5.57 (br, 1H) 6.72 (d, 2H), 6.98 (d, 2H). The mixture was maintained at 110° C. for two hours acetic acid was distilled under vacuum 1 liter of methylene chloride was added to the reaction mixture the unreacted excess hydroquinone was filtered collected (recoverd amount

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

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

Procedure: In 100 ml of acetone is dissolved 15 g (0.0824 moles) of ethyl 2,5-dihydroxybenzoate, 13.9 g (0.110 mole) benzyl chloride and 34.1 g (0.247 mole) potassium carbonate. The mixture is heated to its reflux temperature and maintained at reflux for 22 hours. The solution is filtered and the residue is washed with acetone. The filtrate and washings are concentrated, and the residue is dissolved in diethyl ether. The ether extracts are washed twice with water then with saturated sodium chloride solution and finally dried over magnesium sulfate. The magnesium sulfate is removed by filtration and the solution is evaporated to provide a suspension of product which is triturated with hexane and dried to provide a solid. The solid is recrystallized from hexane to provide ethyl 5-benzyloxy-2-hydroxybenzoate, m.p. 71.5°-73° C. The mixture is heated to its reflux temperature maintained at reflux for 22 hours The solution is filtered the residue is washed with acetone The filtrate and washings are concentrated the residue is dissolved in diethyl ether The ether extracts are washed twice with water with saturated sodium chloride solution and finally dried over magnesium sulfate The magnesium sulfate is removed by filtration the solution is evaporated to provide a suspension of product which is triturated with hexane dried to provide a solid The solid is recrystallized from hexane

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

Procedure: In 100 ml of acetone is dissolved 15 g (0.0824 moles) of ethyl 2,5-dihydroxybenzoate, 13.9 g (0.110 mole) benzyl chloride and 34.1 g (0.247 mole) potassium carbonate. The mixture is heated to its reflux temperature and maintained at reflux for 22 hours. The solution is filtered and the residue is washed with acetone. The filtrate and washings are concentrated, and the residue is dissolved in diethyl ether. The ether extracts are washed twice with water then with saturated sodium chloride solution and finally dried over magnesium sulfate. The magnesium sulfate is removed by filtration and the solution is evaporated to provide a suspension of product which is triturated with hexane and dried to provide a solid. The solid is recrystallized from hexane to provide ethyl 5-benzyloxy-2-hydroxybenzoate, m.p. 71.5°-73° C. The mixture is heated to its reflux temperature maintained at reflux for 22 hours The solution is filtered the residue is washed with acetone The filtrate and washings are concentrated the residue is dissolved in diethyl ether The ether extracts are washed twice with water with saturated sodium chloride solution and finally dried over magnesium sulfate The magnesium sulfate is removed by filtration the solution is evaporated to provide a suspension of product which is triturated with hexane dried to provide a solid The solid is recrystallized from hexane

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

Procedure: Using the general method of Example XXIII Part A, 31.2 g (0.20 mole) of ethyl iodide was reacted with 27.3 g (0.15 mole) of ethyl 2,5-dihydroxybenzoate to provide 22 g of white crystalline ethyl 5-ethoxy-2-hydroxybenzoate, m.p. 64°-66° C.

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

Procedure: In 100 ml of acetone is dissolved 15 g (0.0824 moles) of ethyl 2,5-dihydroxybenzoate, 13.9 g (0.110 mole) benzyl chloride and 34.1 g (0.247 mole) potassium carbonate. The mixture is heated to its reflux temperature and maintained at reflux for 22 hours. The solution is filtered and the residue is washed with acetone. The filtrate and washings are concentrated, and the residue is dissolved in diethyl ether. The ether extracts are washed twice with water then with saturated sodium chloride solution and finally dried over magnesium sulfate. The magnesium sulfate is removed by filtration and the solution is evaporated to provide a suspension of product which is triturated with hexane and dried to provide a solid. The solid is recrystallized from hexane to provide ethyl 5-benzyloxy-2-hydroxybenzoate, m.p. 71.5°-73° C. The mixture is heated to its reflux temperature maintained at reflux for 22 hours The solution is filtered the residue is washed with acetone The filtrate and washings are concentrated the residue is dissolved in diethyl ether The ether extracts are washed twice with water with saturated sodium chloride solution and finally dried over magnesium sulfate The magnesium sulfate is removed by filtration the solution is evaporated to provide a suspension of product which is triturated with hexane dried to provide a solid The solid is recrystallized from hexane

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In the solution of 220 g(2 mol) of hydroquinone in 500 ml of acetic acid, 108.5 g(1 mol) of ethyl chloroformate was drop-added for one hour while agitating the solution at 110° C. The mixture was maintained at 110° C. for two hours, and acetic acid was distilled under vacuum. 1 liter of methylene chloride was added to the reaction mixture, and the unreacted excess hydroquinone was filtered and collected (recoverd amount: 110 g, recycled without any purification process). A desired mono ethoxycarbonyl hydroquinone was obtained by evaporating the residue under vacuum. (Yield: 164.6 g(98%). mp: 81-82° C., 1H-NMR(200 MHz, CDCl3, ppm) 1.38 (t, 3H), 4.31 (q, 2H), 5.57 (br, 1H) 6.72 (d, 2H), 6.98 (d, 2H). The mixture was maintained at 110° C. for two hours acetic acid was distilled under vacuum 1 liter of methylene chloride was added to the reaction mixture the unreacted excess hydroquinone was filtered collected (recoverd amount