Diethyl 1,4-dihydroxynaphthalene-2,3-dicarboxylate

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

Procedure: Bromoethane (0.359 g, 3.29 mmol) was added to a stirred solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (1 g, 3.29 mmol) and potassium carbonate (0.454 g, 3.29 mmol) in acetone (25 ml). The reaction mixture was refluxed for 24 hours under an atmosphere of argon. The resulting mixture was evaporated and the residue was partitioned between 2× ethylacetate and water. The combined organics were washed with water and dried over magnesium sulphate. The orange oil was purified by chromatography on silica gel, eluting with ethyl acetate (0-10%) in hexane to give the title compound as a clear oil (0.661 g, 1.99 mmol). LC/MS: Rt=3.63, [MH]− 331. The reaction mixture was refluxed for 24 hours under an atmosphere of argon The resulting mixture was evaporated the residue was partitioned between 2× ethylacetate and water The combined organics were washed with water dried over magnesium sulphate The orange oil was purified by chromatography on silica gel eluting with ethyl acetate (0-10%) in hexane

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

Procedure: Bromoethane (0.359 g, 3.29 mmol) was added to a stirred solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (1 g, 3.29 mmol) and potassium carbonate (0.454 g, 3.29 mmol) in acetone (25 ml). The reaction mixture was refluxed for 24 hours under an atmosphere of argon. The resulting mixture was evaporated and the residue was partitioned between 2× ethylacetate and water. The combined organics were washed with water and dried over magnesium sulphate. The orange oil was purified by chromatography on silica gel, eluting with ethyl acetate (0-10%) in hexane to give the title compound as a clear oil (0.661 g, 1.99 mmol). LC/MS: Rt=3.63, [MH]− 331. The reaction mixture was refluxed for 24 hours under an atmosphere of argon The resulting mixture was evaporated the residue was partitioned between 2× ethylacetate and water The combined organics were washed with water dried over magnesium sulphate The orange oil was purified by chromatography on silica gel eluting with ethyl acetate (0-10%) in hexane

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

Procedure: Benzylbromide (2.95 ml, 24.7 mmol) was added to a stirred solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (3 g, 9.87 mmol) and potassium carbonate (3.40 g, 24.7 mmol) in acetone (100 ml). The reaction mixture was refluxed for 18 hours under an atmosphere of argon. The resulting mixture was evaporated and the reaction mixture triturated with water. The resulting tan coloured solid was collected by filtration and washed with water then dried under vacuum to give the title compound (5.23 g, 10.8 mmol). LC/MS: Rt=4.13, [MH]+ 485. The reaction mixture was refluxed for 18 hours under an atmosphere of argon The resulting mixture was evaporated the reaction mixture triturated with water was collected by filtration washed with water then dried under vacuum

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate* (11 g, 36.1 mmol) was dissolved in acetone (180 ml) and potassium carbonate (24.9 g, 180.5 mmol) added and stirred. 1-Bromopropane (13.1 ml, 144.4 mmol) was added and the reaction mixture was heated at reflux (60° C.) overnight under argon. The reaction was cooled to room temperature and the inorganic solid filtered off. The solvent was evaporated to give an orange brown oil. The residue was taken up in toluene and washed with 5% potassium hydroxide solution, brine and dried over magnesium sulphate. Solvent was removed under vacuum to give a brown oil which was purified by chromatography on silica gel eluting with, 10% ethyl acetate in hexane. The clean fractions were evaporated to give the title compound as yellow oil (11.45 g, 29.5 mmol). the reaction mixture was heated The reaction was cooled to room temperature the inorganic solid filtered off The solvent was evaporated to give an orange brown oil washed with 5% potassium hydroxide solution, brine dried over magnesium sulphate Solvent was removed under vacuum to give a brown oil which was purified by chromatography on silica gel eluting with, 10% ethyl acetate in hexane The clean fractions were evaporated

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate* (11 g, 36.1 mmol) was dissolved in acetone (180 ml) and potassium carbonate (24.9 g, 180.5 mmol) added and stirred. 1-Bromopropane (13.1 ml, 144.4 mmol) was added and the reaction mixture was heated at reflux (60° C.) overnight under argon. The reaction was cooled to room temperature and the inorganic solid filtered off. The solvent was evaporated to give an orange brown oil. The residue was taken up in toluene and washed with 5% potassium hydroxide solution, brine and dried over magnesium sulphate. Solvent was removed under vacuum to give a brown oil which was purified by chromatography on silica gel eluting with, 10% ethyl acetate in hexane. The clean fractions were evaporated to give the title compound as yellow oil (11.45 g, 29.5 mmol). the reaction mixture was heated The reaction was cooled to room temperature the inorganic solid filtered off The solvent was evaporated to give an orange brown oil washed with 5% potassium hydroxide solution, brine dried over magnesium sulphate Solvent was removed under vacuum to give a brown oil which was purified by chromatography on silica gel eluting with, 10% ethyl acetate in hexane The clean fractions were evaporated

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

Procedure: Iodoethane (70 g) was added to a solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (35 g) in ethanolic sodium ethoxide, prepared from sodium (7.6 g) and ethanol (250 ml), and the mixture was heated under reflux for 3 hours. After keeping overnight at room temperature, the mixture was poured onto ice-hydrochloric acid (500 ml). The oil was separated, washed with aqueous sodium bicarbonate and crystallised from ethanol to give diethyl 1,4-diethoxy-2,3-naphthalenedicarboxylate, (IV) m.p. 68°. the mixture was heated under reflux for 3 hours the mixture was poured onto ice-hydrochloric acid (500 ml) The oil was separated washed with aqueous sodium bicarbonate crystallised from ethanol

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

Procedure: Iodoethane (70 g) was added to a solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (35 g) in ethanolic sodium ethoxide, prepared from sodium (7.6 g) and ethanol (250 ml), and the mixture was heated under reflux for 3 hours. After keeping overnight at room temperature, the mixture was poured onto ice-hydrochloric acid (500 ml). The oil was separated, washed with aqueous sodium bicarbonate and crystallised from ethanol to give diethyl 1,4-diethoxy-2,3-naphthalenedicarboxylate, (IV) m.p. 68°. the mixture was heated under reflux for 3 hours the mixture was poured onto ice-hydrochloric acid (500 ml) The oil was separated washed with aqueous sodium bicarbonate crystallised from ethanol

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

Procedure: Bromoethane (0.359 g, 3.29 mmol) was added to a stirred solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (1 g, 3.29 mmol) and potassium carbonate (0.454 g, 3.29 mmol) in acetone (25 ml). The reaction mixture was refluxed for 24 hours under an atmosphere of argon. The resulting mixture was evaporated and the residue was partitioned between 2× ethylacetate and water. The combined organics were washed with water and dried over magnesium sulphate. The orange oil was purified by chromatography on silica gel, eluting with ethyl acetate (0-10%) in hexane to give the title compound as a clear oil (0.661 g, 1.99 mmol). LC/MS: Rt=3.63, [MH]− 331. The reaction mixture was refluxed for 24 hours under an atmosphere of argon The resulting mixture was evaporated the residue was partitioned between 2× ethylacetate and water The combined organics were washed with water dried over magnesium sulphate The orange oil was purified by chromatography on silica gel eluting with ethyl acetate (0-10%) in hexane

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

Procedure: Benzylbromide (2.95 ml, 24.7 mmol) was added to a stirred solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (3 g, 9.87 mmol) and potassium carbonate (3.40 g, 24.7 mmol) in acetone (100 ml). The reaction mixture was refluxed for 18 hours under an atmosphere of argon. The resulting mixture was evaporated and the reaction mixture triturated with water. The resulting tan coloured solid was collected by filtration and washed with water then dried under vacuum to give the title compound (5.23 g, 10.8 mmol). LC/MS: Rt=4.13, [MH]+ 485. The reaction mixture was refluxed for 18 hours under an atmosphere of argon The resulting mixture was evaporated the reaction mixture triturated with water was collected by filtration washed with water then dried under vacuum

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

Procedure: Bromoethane (0.359 g, 3.29 mmol) was added to a stirred solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (1 g, 3.29 mmol) and potassium carbonate (0.454 g, 3.29 mmol) in acetone (25 ml). The reaction mixture was refluxed for 24 hours under an atmosphere of argon. The resulting mixture was evaporated and the residue was partitioned between 2× ethylacetate and water. The combined organics were washed with water and dried over magnesium sulphate. The orange oil was purified by chromatography on silica gel, eluting with ethyl acetate (0-10%) in hexane to give the title compound as a clear oil (0.661 g, 1.99 mmol). LC/MS: Rt=3.63, [MH]− 331. The reaction mixture was refluxed for 24 hours under an atmosphere of argon The resulting mixture was evaporated the residue was partitioned between 2× ethylacetate and water The combined organics were washed with water dried over magnesium sulphate The orange oil was purified by chromatography on silica gel eluting with ethyl acetate (0-10%) in hexane

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

Procedure: Benzylbromide (2.95 ml, 24.7 mmol) was added to a stirred solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (3 g, 9.87 mmol) and potassium carbonate (3.40 g, 24.7 mmol) in acetone (100 ml). The reaction mixture was refluxed for 18 hours under an atmosphere of argon. The resulting mixture was evaporated and the reaction mixture triturated with water. The resulting tan coloured solid was collected by filtration and washed with water then dried under vacuum to give the title compound (5.23 g, 10.8 mmol). LC/MS: Rt=4.13, [MH]+ 485. The reaction mixture was refluxed for 18 hours under an atmosphere of argon The resulting mixture was evaporated the reaction mixture triturated with water was collected by filtration washed with water then dried under vacuum

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

Procedure: Bromoethane (0.359 g, 3.29 mmol) was added to a stirred solution of diethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (1 g, 3.29 mmol) and potassium carbonate (0.454 g, 3.29 mmol) in acetone (25 ml). The reaction mixture was refluxed for 24 hours under an atmosphere of argon. The resulting mixture was evaporated and the residue was partitioned between 2× ethylacetate and water. The combined organics were washed with water and dried over magnesium sulphate. The orange oil was purified by chromatography on silica gel, eluting with ethyl acetate (0-10%) in hexane to give the title compound as a clear oil (0.661 g, 1.99 mmol). LC/MS: Rt=3.63, [MH]− 331. The reaction mixture was refluxed for 24 hours under an atmosphere of argon The resulting mixture was evaporated the residue was partitioned between 2× ethylacetate and water The combined organics were washed with water dried over magnesium sulphate The orange oil was purified by chromatography on silica gel eluting with ethyl acetate (0-10%) in hexane