5-bromo-2-(trifluoromethoxy)benzaldehyde

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

Procedure: To a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (2.0 g, 7.43 mmol) in anhydrous dichloromethane (40 ml) at room temperature is added boron trifluoride etherate (1.13 ml, 8.92 mmol) then 1,2-bis(trimethylsiloxy)cyclobutene (2.86 ml, 11.2 mmol). The mixture is stirred at room temperature for 23 hours, followed by addition of distilled water (1.2 ml) and additional boron trifluoride etherate (14.1 ml, 112 mmol). After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) and extracted with dichloromethane (2×50 ml). The crude product is extracted into 0.5 M aqueous potassium carbonate solution (×3), then the aqueous phase is acidified to pH 1 with concentrated hydrochloric acid. Final extraction with dichloromethane (×3) is followed by washing with brine then drying over magnesium sulfate. Filtration then concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC to afford 2-(5-bromo-2-trifluoromethoxyphenyl)cyclopentane-1,3-dione. After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) extracted with dichloromethane (2×50 ml) The crude product is extracted into 0.5 M aqueous potassium carbonate solution (×3) Final extraction with dichloromethane (×3) by washing with brine then drying over magnesium sulfate Filtration concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To an ice-cold solution of 2,2,5,5-tetramethyldihydrofuran-3-one (2.84 g, 20.00 mmol) in anhydrous 1,2-dimethoxyethane (6 ml) is added sodium methoxide (1.19 g, 22.04 mmol) in one portion. After stirring at this temperature for 5 minutes a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (4.84 g, 18.00 mmol) in 1,2-dimethoxyethane (6 ml) is added dropwise over 10 mins, followed by stirring at 0° C. for a further 1 hour. After warming to room temperature the reaction mixture is diluted with ether and washed with 2M hydrochloric acid (×2). Organic fractions are combined, dried over magnesium sulphate, filtered and the filtrate evaporated in vacuo to afford 4-[1-(5-bromo-2-trifluoromethoxyphenyl)-methylidene]-2,2,5,5-tetramethyldihydrofuran-3-one (7.06 g) as an orange liquid. is added dropwise over 10 mins After warming to room temperature the reaction mixture washed with 2M hydrochloric acid (×2) dried over magnesium sulphate filtered the filtrate evaporated in vacuo

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To an ice-cold solution of 2,2,5,5-tetramethyldihydrofuran-3-one (2.84 g, 20.00 mmol) in anhydrous 1,2-dimethoxyethane (6 ml) is added sodium methoxide (1.19 g, 22.04 mmol) in one portion. After stirring at this temperature for 5 minutes a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (4.84 g, 18.00 mmol) in 1,2-dimethoxyethane (6 ml) is added dropwise over 10 mins, followed by stirring at 0° C. for a further 1 hour. After warming to room temperature the reaction mixture is diluted with ether and washed with 2M hydrochloric acid (×2). Organic fractions are combined, dried over magnesium sulfate, filtered and the filtrate evaporated in vacuo to afford 4-[1-(5-bromo-2-trifluoromethoxyphenyl)-methylidene]-2,2,5,5-tetramethyldihydrofuran-3-one (7.06 g) as an orange liquid. is added dropwise over 10 mins After warming to room temperature the reaction mixture washed with 2M hydrochloric acid (×2) dried over magnesium sulfate filtered the filtrate evaporated in vacuo

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

Procedure: To a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (2.0 g, 7.43 mmol) in anhydrous dichloromethane (40 ml) at room temperature is added boron trifluoride etherate (1.13 ml, 8.92 mmol) then 1,2-bis(trimethylsiloxy)cyclobutene (2.86 ml, 11.2 mmol). The mixture is stirred at room temperature for 23 hours, followed by addition of distilled water (1.2 ml) and additional boron trifluoride etherate (14.1 ml, 112 mmol). After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) and extracted with dichloromethane (2×50 ml). The crude product is extracted into 0.5 M aqueous potassium carbonate solution (×3), then the aqueous phase is acidified to pH 1 with concentrated hydrochloric acid. Final extraction with dichloromethane (×3) is followed by washing with brine then drying over magnesium sulfate. Filtration then concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC to afford 2-(5-bromo-2-trifluoromethoxyphenyl)cyclopentane-1,3-dione. After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) extracted with dichloromethane (2×50 ml) The crude product is extracted into 0.5 M aqueous potassium carbonate solution (×3) Final extraction with dichloromethane (×3) by washing with brine then drying over magnesium sulfate Filtration concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC

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

Procedure: To a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (2.0 g, 7.43 mmol) in anhydrous dichloromethane (40 ml) at room temperature is added boron trifluoride etherate (1.13 ml, 8.92 mmol) then 1,2-bis(trimethylsiloxy)cyclobutene (2.86 ml, 11.2 mmol). The mixture is stirred at room temperature for 23 hours, followed by addition of distilled water (1.2 ml) and additional boron trifluoride etherate (14.1 ml, 112 mmol). After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) and extracted with dichloromethane (2×50 ml). The crude product is extracted into 0.5 M aqueous potassium carbonate solution (×3), then the aqueous phase is acidified to pH 1 with concentrated hydrochloric acid. Final extraction with dichloromethane (×3) is followed by washing with brine then drying over magnesium sulfate. Filtration then concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC to afford 2-(5-bromo-2-trifluoromethoxyphenyl)cyclopentane-1,3-dione. After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) extracted with dichloromethane (2×50 ml) The crude product is extracted into 0.5 M aqueous potassium carbonate solution (×3) Final extraction with dichloromethane (×3) by washing with brine then drying over magnesium sulfate Filtration concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC

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

Procedure: To a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (2.0 g, 7.43 mmol) in anhydrous dichloromethane (40 ml) at room temperature is added boron trifluoride etherate (1.13 ml, 8.92 mmol) then 1,2-bis(trimethylsiloxy)cyclobutene (2.86 ml, 11.2 mmol). The mixture is stirred at room temperature for 23 hours, followed by addition of distilled water (1.2 ml) and additional boron trifluoride etherate (14.1 ml, 112 mmol). After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) and extracted with dichloromethane (2×50 ml). The crude product is extracted from the organic phase by washing with 0.5 M aqueous potassium carbonate solution (×3), then acidified to pH 1 with concentrated hydrochloric acid. Final extraction with dichloromethane (×3) is followed by washing with brine then drying over magnesium sulfate and filtration. Concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC to afford 2-(5-bromo-2-trifluoromethoxyphenyl)cyclopentane-1,3-dione. After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) extracted with dichloromethane (2×50 ml) The crude product is extracted from the organic phase by washing with 0.5 M aqueous potassium carbonate solution (×3) Final extraction with dichloromethane (×3) by washing with brine then drying over magnesium sulfate and filtration Concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC

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

Procedure: To a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (2.0 g, 7.43 mmol) in anhydrous dichloromethane (40 ml) at room temperature is added boron trifluoride etherate (1.13 ml, 8.92 mmol) then 1,2-bis(trimethylsiloxy)cyclobutene (2.86 ml, 11.2 mmol). The mixture is stirred at room temperature for 23 hours, followed by addition of distilled water (1.2 ml) and additional boron trifluoride etherate (14.1 ml, 112 mmol). After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) and extracted with dichloromethane (2×50 ml). The crude product is extracted from the organic phase by washing with 0.5 M aqueous potassium carbonate solution (×3), then acidified to pH 1 with concentrated hydrochloric acid. Final extraction with dichloromethane (×3) is followed by washing with brine then drying over magnesium sulfate and filtration. Concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC to afford 2-(5-bromo-2-trifluoromethoxyphenyl)cyclopentane-1,3-dione. After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) extracted with dichloromethane (2×50 ml) The crude product is extracted from the organic phase by washing with 0.5 M aqueous potassium carbonate solution (×3) Final extraction with dichloromethane (×3) by washing with brine then drying over magnesium sulfate and filtration Concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC

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

Procedure: Triethylamine (1.14 mL, 8.18 mmol) and propylphosphonic anhydride (cyclic trimer) (ca. 1.7 M solution in ethyl acetate, 4.8 mL, 8.18 mmol) were added in this order to a solution of 5-bromo-2-(trifluoromethoxy)benzaldehyde (2.00 g, 7.43 mmol) and hydroxyamine hydrochloride (568 mg, 8.18 mmol) in DMF (7.5 mL), and the mixture was stirred at 100° C. for 8 hours. The reaction solution was poured to a saturated sodium bicarbonate aqueous solution, followed by extraction with ethyl acetate. The obtained organic layer was washed with brine and dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained residue was purified by silica gel column chromatography [elute: hexane/ethyl acetate=100/0-98/2] to obtain the title compound (1.71 g, yield: 86%). followed by extraction with ethyl acetate The obtained organic layer was washed with brine dried over anhydrous sodium sulfate the solvent was distilled off under reduced pressure The obtained residue was purified by silica gel column chromatography [elute: hexane/ethyl acetate=100/0-98/2]

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To an ice-cold solution of 2,2,5,5-tetramethyldihydrofuran-3-one (2.84 g, 20.00 mmol) in anhydrous 1,2-dimethoxyethane (6 ml) is added sodium methoxide (1.19 g, 22.04 mmol) in one portion. After stirring at this temperature for 5 minutes a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (4.84 g, 18.00 mmol) in 1,2-dimethoxyethane (6 ml) is added dropwise over 10 mins, followed by stirring at 0° C. for a further 1hour. After warming to room temperature the reaction mixture is diluted with ether and washed with 2M hydrochloric acid (×2). Organic fractions are combined, dried over magnesium sulphate, filtered and the filtrate evaporated in vacuo to afford 4-[1-(5-bromo-2-trifluoromethoxyphenyl)-methylidene]-2,2,5,5-tetramethyldihydrofuran-3-one (7.06 g) as an orange liquid. is added dropwise over 10 mins After warming to room temperature the reaction mixture washed with 2M hydrochloric acid (×2) dried over magnesium sulphate filtered the filtrate evaporated in vacuo

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To an ice-cold solution of 2,2,5,5-tetramethyldihydrofuran-3-one (2.84 g, 20.00 mmol) in anhydrous 1,2-dimethoxyethane (6 ml) is added sodium methoxide (1.19 g, 22.04 mmol) in one portion. After stirring at this temperature for 5 minutes a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (4.84 g, 18.00 mmol) in 1,2-dimethoxyethane (6 ml) is added dropwise over 10 mins, followed by stirring at 0° C. for a further 1 hour. After warming to room temperature the reaction mixture is diluted with ether and washed with 2M hydrochloric acid (×2). Organic fractions are combined, dried over magnesium sulphate, filtered and the filtrate evaporated in vacuo to afford 4-[1-(5-bromo-2-trifluoromethoxyphenyl)-methylidene]-2,2,5,5-tetramethyldihydrofuran-3-one (7.06 g) as an orange liquid. is added dropwise over 10 mins After warming to room temperature the reaction mixture washed with 2M hydrochloric acid (×2) dried over magnesium sulphate filtered the filtrate evaporated in vacuo

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To an ice-cold solution of 2,2,5,5-tetramethyldihydrofuran-3-one (2.84 g, 20.00 mmol) in anhydrous 1,2-dimethoxyethane (6 ml) is added sodium methoxide (1.19 g, 22.04 mmol) in one portion. After stirring at this temperature for 5 minutes a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (4.84 g, 18.00 mmol) in 1,2-dimethoxyethane (6 ml) is added dropwise over 10 mins, followed by stirring at 0° C. for a further 1 hour. After warming to room temperature the reaction mixture is diluted with ether and washed with 2M hydrochloric acid (×2). Organic fractions are combined, dried over magnesium sulfate, filtered and the filtrate evaporated in vacuo to afford 4-[1-(5-bromo-2-trifluoromethoxyphenyl)-methylidene]-2,2,5,5-tetramethyldihydrofuran-3-one (7.06 g) as an orange liquid. is added dropwise over 10 mins After warming to room temperature the reaction mixture washed with 2M hydrochloric acid (×2) dried over magnesium sulfate filtered the filtrate evaporated in vacuo

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

Procedure: To a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (2.0 g, 7.43 mmol) in anhydrous dichloromethane (40 ml) at room temperature is added boron trifluoride etherate (1.13 ml, 8.92 mmol) then 1,2-bis(trimethylsiloxy)cyclobutene (2.86 ml, 11.2 mmol). The mixture is stirred at room temperature for 23 hours, followed by addition of distilled water (1.2 ml) and additional boron trifluoride etherate (14.1 ml, 112 mmol). After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) and extracted with dichloromethane (2×50 ml). The crude product is extracted into 0.5 M aqueous potassium carbonate solution (×3), then the aqueous phase is acidified to pH 1 with concentrated hydrochloric acid. Final extraction with dichloromethane (×3) is followed by washing with brine then drying over magnesium sulfate. Filtration then concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC to afford 2-(5-bromo-2-trifluoromethoxyphenyl)cyclopentane-1,3-dione. After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) extracted with dichloromethane (2×50 ml) The crude product is extracted into 0.5 M aqueous potassium carbonate solution (×3) Final extraction with dichloromethane (×3) by washing with brine then drying over magnesium sulfate Filtration concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC