ethyl 2-(trifluoromethyl)furan-3-carboxylate

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

Procedure: A solution of 2-trifluoromethyl-furan-3-carboxylic acid ethyl ester (2.2 g, 10.5 mmoles) in tetrahydrofuran (150 ml) was treated portionwise during 0.5 h with lithium aluminium hydride (0.55 g, 14.5 mmoles) under a nitrogen atmosphere. When the addition was complete the mixture was stirred at room temperature for 18 h, then quenched by the addition of excess acetone (1 ml) and then water (1 ml). After diluting with ethyl acetate (200 ml) the grey precipitate was removed by filtration. The filtrate was dried and evaporation of the solvent afforded (2-trifluoromethyl-furan-3-yl)-methanol as a colourless oil. This material was used immediately in the next step. When the addition quenched by the addition of excess acetone (1 ml) After diluting with ethyl acetate (200 ml) the grey precipitate was removed by filtration The filtrate was dried evaporation of the solvent

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

Procedure: A solution of 2-trifluoromethyl-furan-3-carboxylic acid ethyl ester (2.2 g, 10.5 mmoles) in tetrahydrofuran (150 ml) was treated portionwise during 0.5 h with lithium aluminium hydride (0.55 g, 14.5 mmoles) under a nitrogen atmosphere. When the addition was complete the mixture was stirred at room temperature for 18 h, then quenched by the addition of excess acetone (1 ml) and then water (1 ml). After diluting with ethyl acetate (200 ml) the grey precipitate was removed by filtration. The filtrate was dried and evaporation of the solvent afforded (2-trifluoromethyl-furan-3-yl)-methanol as a colourless oil. This material was used immediately in the next step. (ii) A solution of the (2-trifluoromethyl-furan-3-yl)-methanol from (i) in dry dichloromethane (180 ml) was treated with chloro-tri-isopropyl-silane (2.6 g, 13.4 mmoles) and imidazole (1.45 g, 21.3 mmoles) and the mixture was stirred overnight at room temperature. Further aliquots of chloro-tri-isopropyl-silane (0.9 g, 4.64 mmoles) and imidazole (0.5 g, 7.34 mmoles) were added and the mixture was stirred for 3 h. The reaction mixture was diluted with water, the organic phase separated and washed sequentially with 0.1M aqueous hydrochloric acid, water, saturated aqueous sodium bicarbonate, water and brine. After drying, evaporation of the solvents afforded a colourless oil. The oil was distilled under reduced pressure (0.05 torr) in a Kugelruhr apparatus collecting the fraction boiling at an oven temperature of 125±20° C. to afford compound 88 as a colourless oil. When the addition quenched by the addition of excess acetone (1 ml) After diluting with ethyl acetate (200 ml) the grey precipitate was removed by filtration The filtrate was dried evaporation of the solvent

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

Procedure: A solution of 2-trifluoromethyl-furan-3-carboxylic acid ethyl ester (2.2 g, 10.5 mmoles) in tetrahydrofuran (150 ml) was treated portionwise during 0.5 h with lithium aluminium hydride (0.55 g, 14.5 mmoles) under a nitrogen atmosphere. When the addition was complete the mixture was stirred at room temperature for 18 h, then quenched by the addition of excess acetone (1 ml) and then water (1 ml). After diluting with ethyl acetate (200 ml) the grey precipitate was removed by filtration. The filtrate was dried and evaporation of the solvent afforded (2-trifluoromethyl-furan-3-yl)-methanol as a colourless oil. This material was used immediately in the next step. (ii) A solution of the (2-trifluoromethyl-furan-3-yl)-methanol from (i) in dry dichloromethane (180 ml) was treated with chloro-tri-isopropyl-silane (2.6 g, 13.4 mmoles) and imidazole (1.45 g, 21.3 mmoles) and the mixture was stirred overnight at room temperature. Further aliquots of chloro-tri-isopropyl-silane (0.9 g, 4.64 mmoles) and imidazole (0.5 g, 7.34 mmoles) were added and the mixture was stirred for 3 h. The reaction mixture was diluted with water, the organic phase separated and washed sequentially with 0.1M aqueous hydrochloric acid, water, saturated aqueous sodium bicarbonate, water and brine. After drying, evaporation of the solvents afforded a colourless oil. The oil was distilled under reduced pressure (0.05 torr) in a Kugelruhr apparatus collecting the fraction boiling at an oven temperature of 125±20° C. to afford compound 88 as a colourless oil. When the addition quenched by the addition of excess acetone (1 ml) After diluting with ethyl acetate (200 ml) the grey precipitate was removed by filtration The filtrate was dried evaporation of the solvent

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

Procedure: Furanyl-imidazoles were prepared by the TosMIC reaction from aldehydes, which can be obtained either by reduction of acids, esters or amides; or by oxidation of primary alcohols. These procedures are well known in the literature. For example, ethyl 2-trifluoromethyl-furan-3-carboxylate (Scheme 17) prepared from literature procedures (U.S. Pat. No. 5,405,865, Apr. 11, 1995) was converted to an aldehyde by reduction of a Weinreb amide. The aldehyde was then reacted with the TosMIC and methanolic ammonia to yield 4-(2-trifluoromethyl-furan-3-yl)-imidazole.

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

Procedure: 20 g of the product of Stage B were cooled to -60° C. in 200 ml of toluene, 160 ml of diisobutylaluminium hydride were added dropwise. The mixture was stirred for 1 and a half hours at -60° C. and was then poured into sodium potassium double tartrate and extracted with methylene chloride. The solvent was evaporated and the residue was chromatographed on silica (eluent: 7/3 hexane/ethyl acetate) to obtain 16 g of the expected product. extracted with methylene chloride The solvent was evaporated the residue was chromatographed on silica (eluent: 7/3 hexane/ethyl acetate)

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

Procedure: 43.g of the product of Stage A were refluxed for 2 and a half hours in 250 ml of toluene and 3.1 g of toluenesulfonic acid and the reaction mixture was allowed to cool and was chromatographed on silica (eluent: 9/1 hexane/ethyl acetate) to obtain after evaporation of the solvent at 40° C. under 80 mm of Hg, 20 g of the expected product. to cool was chromatographed on silica (eluent: 9/1 hexane/ethyl acetate) to obtain after evaporation of the solvent at 40° C. under 80 mm of Hg, 20 g of the expected product

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

Procedure: A solution of 2-trifluoromethyl-furan-3-carboxylic acid ethyl ester (2.2 g, 10.5 mmoles) in tetrahydrofuran (150 ml) was treated portionwise during 0.5 h with lithium aluminium hydride (0.55 g, 14.5 mmoles) under a nitrogen atmosphere. When the addition was complete the mixture was stirred at room temperature for 18 h, then quenched by the addition of excess acetone (1 ml) and then water (1 ml). After diluting with ethyl acetate (200 ml) the grey precipitate was removed by filtration. The filtrate was dried and evaporation of the solvent afforded (2-trifluoromethyl-furan-3-yl)-methanol as a colourless oil. This material was used immediately in the next step. When the addition quenched by the addition of excess acetone (1 ml) After diluting with ethyl acetate (200 ml) the grey precipitate was removed by filtration The filtrate was dried evaporation of the solvent