2,5-Dibromohydroquinone

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

Procedure: To a solution of 2,5-dibromohydroquinone (1) (5 g, 18.6 mol) in acetonitrile (250 ml) was added cerium ammonium nitrate (21.4 g, 39.0 mmol), in small portions. The clear orange solution was stirred for 10 min at room temperature, diluted with water (80 ml) and extracted with chloroform (3×200 ml). The combined chloroform layers were dried over sodium sulphate and evaporated, yielding 3.5 g (71%) of the quinone (2). extracted with chloroform (3×200 ml) The combined chloroform layers were dried over sodium sulphate evaporated

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

Procedure: 2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield. the reaction mixture was cooled the precipitate formed was filtered washed with methanol The filtrate was evaporated to remove the solvent 2 L of distilled water was added to the residue boiled gently for 1 h cooled The resulting precipitate was collected by filtration washed with water dried in vacuo The crude product was purified by column chromatography a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield

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

Procedure: 2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield. the reaction mixture was cooled the precipitate formed was filtered washed with methanol The filtrate was evaporated to remove the solvent 2 L of distilled water was added to the residue boiled gently for 1 h cooled The resulting precipitate was collected by filtration washed with water dried in vacuo The crude product was purified by column chromatography a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield

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

Procedure: 2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield. the reaction mixture was cooled the precipitate formed was filtered washed with methanol The filtrate was evaporated to remove the solvent 2 L of distilled water was added to the residue boiled gently for 1 h cooled The resulting precipitate was collected by filtration washed with water dried in vacuo The crude product was purified by column chromatography a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield

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

Procedure: 2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH2Cl2:hexanes, 4:6) to get the pure product in 60% yield. the reaction mixture was cooled the precipitate formed was filtered washed with methanol The filtrate was evaporated to remove the solvent 2 L of distilled water was added to the residue boiled gently for 1 h cooled The resulting precipitate was collected by filtration washed with water dried in vacuo The crude product was purified by column chromatography a mixture of solvents (CH2Cl2:hexanes, 4:6) to get the pure product in 60% yield

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

Procedure: A suspension of KOH powder (10.47 g, 186.6 mmol) in dried DMSO (360 mL) was degassed under vigorous stirring for 1 h. 2,5-dibromo-1,4-dihydroxybenzene (5 g, 18.66 mol) and 1-bromohexane (5.8 mL, 41.06 mmol) were added and stirred for 12 h. The solution was concentrated and precipitated in water, filtered, washed with methanol. The product was recrystallized in ethanol, dried in vacuo (4.518 g, 55.5%). 1H NMR(300 MHz, CDCl3): δ 7.08 (s, 2H), 3.95 (t, 4H), 1.8 (m, 4H), 1.49 (m, 4H). 1.37 (m, 8H), 0.9 (t, 6H). was degassed stirred for 12 h The solution was concentrated precipitated in water filtered washed with methanol The product was recrystallized in ethanol dried in vacuo (4.518 g, 55.5%)

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

Procedure: To a solution of 2,5-dibromohydroquinone (1) (5 g, 18.6 mol) in acetonitrile (250 ml) was added cerium ammonium nitrate (21.4 g, 39.0 mmol), in small portions. The clear orange solution was stirred for 10 min at room temperature, diluted with water (80 ml) and extracted with chloroform (3×200 ml). The combined chloroform layers were dried over sodium sulphate and evaporated, yielding 3.5 g (71%) of the quinone (2). extracted with chloroform (3×200 ml) The combined chloroform layers were dried over sodium sulphate evaporated

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

Procedure: 2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield. the reaction mixture was cooled the precipitate formed was filtered washed with methanol The filtrate was evaporated to remove the solvent 2 L of distilled water was added to the residue boiled gently for 1 h cooled The resulting precipitate was collected by filtration washed with water dried in vacuo The crude product was purified by column chromatography a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield

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

Procedure: 2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield. the reaction mixture was cooled the precipitate formed was filtered washed with methanol The filtrate was evaporated to remove the solvent 2 L of distilled water was added to the residue boiled gently for 1 h cooled The resulting precipitate was collected by filtration washed with water dried in vacuo The crude product was purified by column chromatography a mixture of solvents (CH2Cl2: hexanes, 4:6) to get the pure product in 60% yield

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

Procedure: 2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH2Cl2:hexanes, 4:6) to get the pure product in 60% yield. the reaction mixture was cooled the precipitate formed was filtered washed with methanol The filtrate was evaporated to remove the solvent 2 L of distilled water was added to the residue boiled gently for 1 h cooled The resulting precipitate was collected by filtration washed with water dried in vacuo The crude product was purified by column chromatography a mixture of solvents (CH2Cl2:hexanes, 4:6) to get the pure product in 60% yield

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

Procedure: A suspension of KOH powder (10.47 g, 186.6 mmol) in dried DMSO (360 mL) was degassed under vigorous stirring for 1 h. 2,5-dibromo-1,4-dihydroxybenzene (5 g, 18.66 mol) and 1-bromohexane (5.8 mL, 41.06 mmol) were added and stirred for 12 h. The solution was concentrated and precipitated in water, filtered, washed with methanol. The product was recrystallized in ethanol, dried in vacuo (4.518 g, 55.5%). 1H NMR(300 MHz, CDCl3): δ 7.08 (s, 2H), 3.95 (t, 4H), 1.8 (m, 4H), 1.49 (m, 4H). 1.37 (m, 8H), 0.9 (t, 6H). was degassed stirred for 12 h The solution was concentrated precipitated in water filtered washed with methanol The product was recrystallized in ethanol dried in vacuo (4.518 g, 55.5%)