2,4,5-三氟-3-羟基苯甲酸乙酯

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 1.76 g (0.044 moles) of a 60% w/w suspension of sodium hydride in mineral oil was added in small portions, whilst stirring and ice-cooling, to a solution of 8.83 g (0.04 moles) of ethyl 2,4,5-trifluoro-3-hydroxybenzoate [(XXIV), X=X'=F, R16 =C2H5O] [prepared as described in step (a) above] in 40 ml of dimethylformamide and, after the addition was complete, the mixture was stirred, whilst ice-cooling, for an additional 30 minutes. At the end of this time, the reaction mixture was transferred into a 200 ml stainless steel autoclave, and then 100 ml of dimethylformamide containing 28.0 g (0.32 moles) of chlorodifluoromethane were added thereto, and the mixture was stirred under pressure at 95°-100° C. for 5 hours. At the end of this time, the dimethylformamide was removed by distillation under reduced pressure, and water was added to the residue, which was extracted with toluene. The extract was washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by evaporation under reduced pressure. The residue was subjected to silica gel column chromatography, using toluene as the eluent, to give 4.85 g of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate as a colorless liquid. was added in small portions after the addition the mixture was stirred, whilst ice- cooling, for an additional 30 minutes the mixture was stirred under pressure at 95°-100° C. for 5 hours At the end of this time, the dimethylformamide was removed by distillation under reduced pressure, and water was added to the residue, which was extracted with toluene The extract was washed with water dried over anhydrous sodium sulfate the solvent was removed by evaporation under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 5 ml of concentrated sulfuric acid were added to a solution of 20.0 g (0.104 moles) of 2,4,5-trifluoro-3-hydroxybenzoic acid [(XXIII), X=X'=F] (prepared as described in Preparation 13) in 500 ml of ethanol, and the mixture was heated under reflux for 4 hours. The ethanol was then removed by distillation under reduced pressure, and the residue was extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium bicarbonate and with water, in that order, after which it was dried over anhydrous sodium sulfate and then concentrated by evaporation under reduced pressure, to give 16.9 g of ethyl 2,4,5-trifluoro-3-hydroxybenzoate as a colorless powder. the mixture was heated under reflux for 4 hours The ethanol was then removed by distillation under reduced pressure the residue was extracted with ethyl acetate The extract was washed with a saturated aqueous solution of sodium bicarbonate and with water, in that order after which it was dried over anhydrous sodium sulfate concentrated by evaporation under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 1.76 g (0.044 moles) of a 60% w/w suspension of sodium hydride in mineral oil was added in small portions, whilst stirring and ice-cooling, to a solution of 8.83 g (0.04 moles) of ethyl 2,4,5-trifluoro-3-hydroxybenzoate [(XXIV), X=X'=F, R16 =C2H5O] [prepared as described in step (a) above] in 40 ml of dimethylformamide and, after the addition was complete, the mixture was stirred, whilst ice-cooling, for an additional 30 minutes. At the end of this time, the reaction mixture was transferred into a 200 ml stainless steel autoclave, and then 100 ml of dimethylformamide containing 28.0 g (0.32 moles) of chlorodifluoromethane were added thereto, and the mixture was stirred under pressure at 95°-100° C. for 5 hours. At the end of this time, the dimethylformamide was removed by distillation under reduced pressure, and water was added to the residue, which was extracted with toluene. The extract was washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by evaporation under reduced pressure. The residue was subjected to silica gel column chromatography, using toluene as the eluent, to give 4.85 g of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate as a colorless liquid. was added in small portions after the addition the mixture was stirred, whilst ice- cooling, for an additional 30 minutes the mixture was stirred under pressure at 95°-100° C. for 5 hours At the end of this time, the dimethylformamide was removed by distillation under reduced pressure, and water was added to the residue, which was extracted with toluene The extract was washed with water dried over anhydrous sodium sulfate the solvent was removed by evaporation under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 5 ml of concentrated sulfuric acid were added to a solution of 20.0 g (0.104 moles) of 2,4,5-trifluoro-3-hydroxybenzoic acid [(XXIII), X=X'=F] (prepared as described in Preparation 13) in 500 ml of ethanol, and the mixture was heated under reflux for 4 hours. The ethanol was then removed by distillation under reduced pressure, and the residue was extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium bicarbonate and with water, in that order, after which it was dried over anhydrous sodium sulfate and then concentrated by evaporation under reduced pressure, to give 16.9 g of ethyl 2,4,5-trifluoro-3-hydroxybenzoate as a colorless powder. the mixture was heated under reflux for 4 hours The ethanol was then removed by distillation under reduced pressure the residue was extracted with ethyl acetate The extract was washed with a saturated aqueous solution of sodium bicarbonate and with water, in that order after which it was dried over anhydrous sodium sulfate concentrated by evaporation under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 1.76 g (0.044 moles) of a 60% w/w suspension of sodium hydride in mineral oil was added in small portions, whilst stirring and ice-cooling, to a solution of 8.83 g (0.04 moles) of ethyl 2,4,5-trifluoro-3-hydroxybenzoate [(XXIV), X=X'=F, R16 =C2H5O] [prepared as described in step (a) above] in 40 ml of dimethylformamide and, after the addition was complete, the mixture was stirred, whilst ice-cooling, for an additional 30 minutes. At the end of this time, the reaction mixture was transferred into a 200 ml stainless steel autoclave, and then 100 ml of dimethylformamide containing 28.0 g (0.32 moles) of chlorodifluoromethane were added thereto, and the mixture was stirred under pressure at 95°-100° C. for 5 hours. At the end of this time, the dimethylformamide was removed by distillation under reduced pressure, and water was added to the residue, which was extracted with toluene. The extract was washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by evaporation under reduced pressure. The residue was subjected to silica gel column chromatography, using toluene as the eluent, to give 4.85 g of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate as a colorless liquid. was added in small portions after the addition the mixture was stirred, whilst ice- cooling, for an additional 30 minutes the mixture was stirred under pressure at 95°-100° C. for 5 hours At the end of this time, the dimethylformamide was removed by distillation under reduced pressure, and water was added to the residue, which was extracted with toluene The extract was washed with water dried over anhydrous sodium sulfate the solvent was removed by evaporation under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 5 ml of concentrated sulfuric acid were added to a solution of 20.0 g (0.104 moles) of 2,4,5-trifluoro-3-hydroxybenzoic acid [(XXIII), X=X'=F] (prepared as described in Preparation 13) in 500 ml of ethanol, and the mixture was heated under reflux for 4 hours. The ethanol was then removed by distillation under reduced pressure, and the residue was extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium bicarbonate and with water, in that order, after which it was dried over anhydrous sodium sulfate and then concentrated by evaporation under reduced pressure, to give 16.9 g of ethyl 2,4,5-trifluoro-3-hydroxybenzoate as a colorless powder. the mixture was heated under reflux for 4 hours The ethanol was then removed by distillation under reduced pressure the residue was extracted with ethyl acetate The extract was washed with a saturated aqueous solution of sodium bicarbonate and with water, in that order after which it was dried over anhydrous sodium sulfate concentrated by evaporation under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 1.76 g (0.044 moles) of a 60% w/w suspension of sodium hydride in mineral oil was added in small portions, whilst stirring and ice-cooling, to a solution of 8.83 g (0.04 moles) of ethyl 2,4,5-trifluoro-3-hydroxybenzoate [(XXIV), X=X'=F, R16 =C2H5O] [prepared as described in step (a) above] in 40 ml of dimethylformamide and, after the addition was complete, the mixture was stirred, whilst ice-cooling, for an additional 30 minutes. At the end of this time, the reaction mixture was transferred into a 200 ml stainless steel autoclave, and then 100 ml of dimethylformamide containing 28.0 g (0.32 moles) of chlorodifluoromethane were added thereto, and the mixture was stirred under pressure at 95°-100° C. for 5 hours. At the end of this time, the dimethylformamide was removed by distillation under reduced pressure, and water was added to the residue, which was extracted with toluene. The extract was washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by evaporation under reduced pressure. The residue was subjected to silica gel column chromatography, using toluene as the eluent, to give 4.85 g of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate as a colorless liquid. was added in small portions after the addition the mixture was stirred, whilst ice- cooling, for an additional 30 minutes the mixture was stirred under pressure at 95°-100° C. for 5 hours At the end of this time, the dimethylformamide was removed by distillation under reduced pressure, and water was added to the residue, which was extracted with toluene The extract was washed with water dried over anhydrous sodium sulfate the solvent was removed by evaporation under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 5 ml of concentrated sulfuric acid were added to a solution of 20.0 g (0.104 moles) of 2,4,5-trifluoro-3-hydroxybenzoic acid [(XXIII), X=X'=F] (prepared as described in Preparation 13) in 500 ml of ethanol, and the mixture was heated under reflux for 4 hours. The ethanol was then removed by distillation under reduced pressure, and the residue was extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium bicarbonate and with water, in that order, after which it was dried over anhydrous sodium sulfate and then concentrated by evaporation under reduced pressure, to give 16.9 g of ethyl 2,4,5-trifluoro-3-hydroxybenzoate as a colorless powder. the mixture was heated under reflux for 4 hours The ethanol was then removed by distillation under reduced pressure the residue was extracted with ethyl acetate The extract was washed with a saturated aqueous solution of sodium bicarbonate and with water, in that order after which it was dried over anhydrous sodium sulfate concentrated by evaporation under reduced pressure