ethyl 3,4,5-trihydroxybenzoate

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 0.2 ml of 1,2-dibromoethane in 4 ml of dimethylformamide is added dropwise, four times at 2 hour intervals, to a solution, stirred at 100° C., of 2 g of gallic acid ethyl ester and 6.5 g of caesium carbonate in 80 ml of dimethylformamide. After being stirred for a further 2 hours at 100° C. the reaction mixture is concentrated by evaporation and the residue is partitioned between diethyl ether and water. The organic phases are dried over sodium sulfate and concentrated by evaporation. The title compound is obtained from the residue by FC (50 g of silica gel, methylene chloride-methanol=8:2): Rf (methylene chloride/methanol=8:2)=0.39. is concentrated by evaporation the residue is partitioned between diethyl ether and water The organic phases are dried over sodium sulfate concentrated by evaporation

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 0.2 ml of 1,2-dibromoethane in 4 ml of dimethylformamide is added dropwise, four times at 2 hour intervals, to a solution, stirred at 100° C., of 2 g of gallic acid ethyl ester and 6.5 g of caesium carbonate in 80 ml of dimethylformamide. After being stirred for a further 2 hours at 100° C. the reaction mixture is concentrated by evaporation and the residue is partitioned between diethyl ether and water. The organic phases are dried over sodium sulfate and concentrated by evaporation. The title compound is obtained from the residue by FC (50 g of silica gel, methylene chloride-methanol=8:2): Rf (methylene chloride/methanol=8:2)=0.39. is concentrated by evaporation the residue is partitioned between diethyl ether and water The organic phases are dried over sodium sulfate concentrated by evaporation

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

Procedure: 5 g (25.2 mmol) of 3,4,5-Trihydroxy-benzoic acid ethyl ester was dissolved in 50 ml of DMF and treated at 0° C. with 13.95 g (101 mmol) of potassium carbonate and 4.39 g (25.2 mmol) of dibromomethane. The reaction solution was heated at 60° C. for 3 h. The solvent was removed under reduced pressure, the residue was taken-up in ethyl acetate and the solution was washed three times with water and twice with saturated aqueous sodium chloride. The organic phase was dried with magnesium sulphate, filtered and the solvent was removed under reduced pressure. The residue was chromatographed on silica gel eluting with n-heptane/ethyl acetate (3/1). The solvent was removed under reduced pressure the solution was washed three times with water The organic phase was dried with magnesium sulphate filtered the solvent was removed under reduced pressure The residue was chromatographed on silica gel eluting with n-heptane/ethyl acetate (3/1)

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

Procedure: 5 g (25.2 mmol) of 3,4,5-Trihydroxy-benzoic acid ethyl ester was dissolved in 50 ml of DMF and treated at 0° C. with 13.95 g (101 mmol) of potassium carbonate and 4.39 g (25.2 mmol) of dibromomethane. The reaction solution was heated at 60° C. for 3 h. The solvent was removed under reduced pressure, the residue was taken-up in ethyl acetate and the solution was washed three times with water and twice with saturated aqueous sodium chloride. The organic phase was dried with magnesium sulphate, filtered and the solvent was removed under reduced pressure. The residue was chromatographed on silica gel eluting with n-heptane/ethyl acetate (3/1). The solvent was removed under reduced pressure the solution was washed three times with water The organic phase was dried with magnesium sulphate filtered the solvent was removed under reduced pressure The residue was chromatographed on silica gel eluting with n-heptane/ethyl acetate (3/1)

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 0.2 ml of 1,2-dibromoethane in 4 ml of dimethylformamide is added dropwise, four times at 2 hour intervals, to a solution, stirred at 100° C., of 2 g of gallic acid ethyl ester and 6.5 g of caesium carbonate in 80 ml of dimethylformamide. After being stirred for a further 2 hours at 100° C. the reaction mixture is concentrated by evaporation and the residue is partitioned between diethyl ether and water. The organic phases are dried over sodium sulfate and concentrated by evaporation. The title compound is obtained from the residue by FC (50 g of silica gel, methylene chloride-methanol=8:2): Rf (methylene chloride/methanol=8:2)=0.39. is concentrated by evaporation the residue is partitioned between diethyl ether and water The organic phases are dried over sodium sulfate concentrated by evaporation

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

Procedure: Ethyl gallate (7.92 g, commercially available, Fluka), and K2CO3 (27.6 g) in DMF (40 ml) were treated with allyl bromide (13.5 ml) as above, to give ethyl 3,4,5-triallyloxybenzoate (14 g): NMR (CDCl3) 1.49 (t, 3H); 4.35 (q, 2H); 4.62 (m, 6H); 5.15-5.48 (m, 6H); 6.00-6.28 (m, 3H); 7.29 (s, 1H). This crude ester was hydrolysed essentially as above to give 3,4,5-triallyloxybenzoic acid(10.4 g): NMR (CDCl3) 4.64 (m, 6H); 5.15-5.51 (m, 6H); 6.00-6.20 (m, 3H); 7.35 (s, 1H).

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

Procedure: Ethyl gallate (7.92 g, commercially available, Fluka), and K2CO3 (27.6 g) in DMF (40 ml) were treated with allyl bromide (13.5 ml) as above, to give ethyl 3,4,5-triallyloxybenzoate (14 g): NMR (CDCl3) 1.49 (t, 3H); 4.35 (q, 2H); 4.62 (m, 6H); 5.15-5.48 (m, 6H); 6.00-6.28 (m, 3H); 7.29 (s, 1H). This crude ester was hydrolysed essentially as above to give 3,4,5-triallyloxybenzoic acid(10.4 g): NMR (CDCl3) 4.64 (m, 6H); 5.15-5.51 (m, 6H); 6.00-6.20 (m, 3H); 7.35 (s, 1H).

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 0.2 ml of 1,2-dibromoethane in 4 ml of dimethylformamide is added dropwise, four times at 2 hour intervals, to a solution, stirred at 100° C., of 2 g of gallic acid ethyl ester and 6.5 g of caesium carbonate in 80 ml of dimethylformamide. After being stirred for a further 2 hours at 100° C. the reaction mixture is concentrated by evaporation and the residue is partitioned between diethyl ether and water. The organic phases are dried over sodium sulfate and concentrated by evaporation. The title compound is obtained from the residue by FC (50 g of silica gel, methylene chloride-methanol=8:2): Rf (methylene chloride/methanol=8:2)=0.39. is concentrated by evaporation the residue is partitioned between diethyl ether and water The organic phases are dried over sodium sulfate concentrated by evaporation

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 0.2 ml of 1,2-dibromoethane in 4 ml of dimethylformamide is added dropwise, four times at 2 hour intervals, to a solution, stirred at 100° C., of 2 g of gallic acid ethyl ester and 6.5 g of caesium carbonate in 80 ml of dimethylformamide. After being stirred for a further 2 hours at 100° C. the reaction mixture is concentrated by evaporation and the residue is partitioned between diethyl ether and water. The organic phases are dried over sodium sulfate and concentrated by evaporation. The title compound is obtained from the residue by FC (50 g of silica gel, methylene chloride-methanol=8:2): Rf (methylene chloride/methanol=8:2)=0.39. is concentrated by evaporation the residue is partitioned between diethyl ether and water The organic phases are dried over sodium sulfate concentrated by evaporation

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 0.2 ml of 1,2-dibromoethane in 4 ml of dimethylformamide is added dropwise, four times at 2 hour intervals, to a solution, stirred at 100° C., of 2 g of gallic acid ethyl ester and 6.5 g of caesium carbonate in 80 ml of dimethylformamide. After being stirred for a further 2 hours at 100° C. the reaction mixture is concentrated by evaporation and the residue is partitioned between diethyl ether and water. The organic phases are dried over sodium sulfate and concentrated by evaporation. The title compound is obtained from the residue by FC (50 g of silica gel, methylene chloride-methanol=8:2): Rf (methylene chloride/methanol=8:2)=0.39. is concentrated by evaporation the residue is partitioned between diethyl ether and water The organic phases are dried over sodium sulfate concentrated by evaporation

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

Procedure: Ethyl gallate (7.92 g, commercially available, Fluka), and K2CO3 (27.6 g) in DMF (40 ml) were treated with allyl bromide (13.5 ml) as above, to give ethyl 3,4,5-triallyloxybenzoate acid (14 g): NMR (CDCl3) 1.49 (t, 3H); 4.35 (q, 2H); 4.62 (m, 6H); 5.15-5.48 (m, 6H); 6.00-6.28 (m, 3H); 7.29 (s, 1H). This crude ester was hydrolysed essentially as above to give 3,4,5-triallyloxybenzoic acid (10.4 g): NMR (CDCl3) 4.64 (m, 6H); 5.15-5.51 (m, 6H); 6.00-6.20 (m, 3H); 7.35 (s, 1H).

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 0.2 ml of 1,2-dibromoethane in 4 ml of dimethylformamide is added dropwise, four times at 2 hour intervals, to a solution, stirred at 100° C., of 2 g of gallic acid ethyl ester and 6.5 g of caesium carbonate in 80 ml of dimethylformamide. After being stirred for a further 2 hours at 100° C. the reaction mixture is concentrated by evaporation and the residue is partitioned between diethyl ether and water. The organic phases are dried over sodium sulfate and concentrated by evaporation. The title compound is obtained from the residue by FC (50 g of silica gel, methylene chloride-methanol=8:2): Rf (methylene chloride/methanol=8:2)=0.39. is concentrated by evaporation the residue is partitioned between diethyl ether and water The organic phases are dried over sodium sulfate concentrated by evaporation