ethyl 3-(difluoromethoxy)-2,4,5-trifluorobenzoate

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:

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

Procedure: 20 ml of a 6% w/v aqueous solution of sodium hydroxide were added to a solution of 5.79 g (0.021 moles) of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate [(XXVI), X=X'=F, R16 =C2H5O] [prepared as described in step (b) above] in 40 ml of ethanol, and the mixture was left at room temperature overnight. The reaction mixture was then acidified by the addition of 3.5 ml of concentrated aqueous hydrochloric acid, and, after concentration by evaporation under reduced pressure, it was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by distillation under reduced pressure, to give 5.22 g of 3-difluoromethoxy-2,4,5-trifluorobenzoic acid as a colorless powder, melting at 68°-70° C. after concentration by evaporation under reduced pressure, it was extracted with ethyl acetate The extract was washed with water dried over anhydrous sodium sulfate the solvent was removed by distillation under reduced pressure

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

Procedure: 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

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

Procedure: 20 ml of a 6% w/v aqueous solution of sodium hydroxide were added to a solution of 5.79 g (0.021 moles) of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate [(XXVI), X=X'=F, R16 =C2H5O] [prepared as described in step (b) above] in 40 ml of ethanol, and the mixture was left at room temperature overnight. The reaction mixture was then acidified by the addition of 3.5 ml of concentrated aqueous hydrochloric acid, and, after concentration by evaporation under reduced pressure, it was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by distillation under reduced pressure, to give 5.22 g of 3-difluoromethoxy-2,4,5-trifluorobenzoic acid as a colorless powder, melting at 68°-70° C. after concentration by evaporation under reduced pressure, it was extracted with ethyl acetate The extract was washed with water dried over anhydrous sodium sulfate the solvent was removed by distillation under reduced pressure

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

Procedure: 20 ml of a 6% w/v aqueous solution of sodium hydroxide were added to a solution of 5.79 g (0.021 moles) of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate [(XXVI), X=X'=F, R16 =C2H5O] [prepared as described in step (b) above] in 40 ml of ethanol, and the mixture was left at room temperature overnight. The reaction mixture was then acidified by the addition of 3.5 ml of concentrated aqueous hydrochloric acid, and, after concentration by evaporation under reduced pressure, it was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by distillation under reduced pressure, to give 5.22 g of 3-difluoromethoxy-2,4,5-trifluorobenzoic acid as a colorless powder, melting at 68°-70° C. after concentration by evaporation under reduced pressure, it was extracted with ethyl acetate The extract was washed with water dried over anhydrous sodium sulfate the solvent was removed by distillation under reduced pressure

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

Procedure: 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

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

Procedure: In 66 ml of dimethyl sulfoxide was dissolved 13.2 g of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate, and to this solution was added 7.3 g of sodium azide, after which the resulting mixture was stirred at room temperature for five hours. The reaction mixture was added to a mixed solvent of 150 ml of ethyl acetate and 150 ml of ice water and the pH was adjusted to 2 with 6N hydrochloric acid, after which the organic layer formed was separated, then washed successively with water and a saturated saline solution, and thereafter dried over anhydrous magnesium sulfate. The solvent was then removed by distillation under reduced pressure. The residue obtained was purified by a column chromatography (eluent: n-hexane:ethyl acetate=10:1), to obtain 13.9 g of colorless, oily ethyl 4-azido-2,5-difluoro-3-difluorome-thoxybenzoate. after which the organic layer formed was separated washed successively with water a saturated saline solution, and thereafter dried over anhydrous magnesium sulfate The solvent was then removed by distillation under reduced pressure The residue obtained was purified by a column chromatography (eluent: n-hexane:ethyl acetate=10:1)

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

Procedure: 20 ml of a 6% w/v aqueous solution of sodium hydroxide were added to a solution of 5.79 g (0.021 moles) of ethyl 3-difluoromethoxy-2,4,5-trifluorobenzoate [(XXVI), X=X'=F, R16 =C2H5O] [prepared as described in step (b) above] in 40 ml of ethanol, and the mixture was left at room temperature overnight. The reaction mixture was then acidified by the addition of 3.5 ml of concentrated aqueous hydrochloric acid, and, after concentration by evaporation under reduced pressure, it was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by distillation under reduced pressure, to give 5.22 g of 3-difluoromethoxy-2,4,5-trifluorobenzoic acid as a colorless powder, melting at 68°-70° C. after concentration by evaporation under reduced pressure, it was extracted with ethyl acetate The extract was washed with water dried over anhydrous sodium sulfate the solvent was removed by distillation under reduced pressure

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

Procedure: 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