ethyl 3,5-difluorobenzoate

Conditions: temp:80.01; pressure:0.00; stir:

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

Procedure: 10.0 mL of conc. HNO3 at 0° C. was slowly treated with 20.0 mL of conc. H2SO4, then 7.6 g (40 mmol) of 3,5-difluoro-benzoic acid ethyl ester. The reaction mixture was warmed up to room temperature and stirred overnight. This mixture was poured into a beaker containing ice. The resulting mixture was extracted with ethyl acetate, washed with cold water and evaporated to produce 7.4 g (32 mmol, 80%) of 3,5-difluoro-2-nitro-benzoic acid ethyl ester. LCMS: 232 (M+1)+. This mixture was poured into a beaker containing ice The resulting mixture was extracted with ethyl acetate washed with cold water evaporated

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

Procedure: 10.0 mL of conc. HNO3 at 0° C. was slowly treated with 20.0 mL of conc. H2SO4, then 7.6 g (40 mmol) of 3,5-difluoro-benzoic acid ethyl ester. The reaction mixture was warmed up to room temperature and stirred overnight. This mixture was poured into a beaker containing ice. The resulting mixture was extracted with ethyl acetate, washed with cold water and evaporated to produce 7.4 g (32 mmol, 80%) of 3,5-difluoro-2-nitro-benzoic acid ethyl ester. LCMS: 232 (M+1)+. This mixture was poured into a beaker containing ice The resulting mixture was extracted with ethyl acetate washed with cold water evaporated

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Diisopropylamine (10.6 mL, 76 mmol) was dissolved in dry THF (10 mL) and the solution cooled to −20° C. A solution of n-butyllithium (2.5N in hexanes, 30.5 mL, 76 mmol) was added slowly at such a rate as to keep the internal temperature below 0° C. After stirring for 5 min, the solution was cooled to −20° C. and added to a solution of acetonitrile (2.37 mL, 45.3 mmol) and ethyl 3,5-difluorobenzoate (6.23 g, 36.2 mmol) in dry THF (18 mL) at such a rate as to keep the temperature below −40° C. A further 10 mL of dry THF was used to transfer the remaining lithium diisopropylamide to the reaction. The reaction was allowed to warm to ambient over 2 h before being quenched with saturated aqueous ammonium chloride solution. The reaction was extracted with ethyl acetate (×2) and the extracts discarded. The aqueous was acidified with 2N HCl and extracted with ethyl acetate. The organic extract was washed with 2N HCl and brine before being dried over MgSO4, filtered and evaporated. Purification using chromatography (silica gel, gradient 5 to 100% ethyl acetate/isohexane) gave 3-(3,5-difluorophenyl)-3-oxopropanenitrile as a yellow solid (2.82 g). the internal temperature below 0° C the solution was cooled to −20° C. the temperature below −40° C to the reaction to warm to ambient over 2 h before being quenched with saturated aqueous ammonium chloride solution The reaction was extracted with ethyl acetate (×2) extracted with ethyl acetate The organic extract was washed with 2N HCl and brine before being dried over MgSO4 filtered evaporated Purification

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Diisopropylamine (10.6 mL, 76 mmol) was dissolved in dry THF (10 mL) and the solution cooled to −20° C. A solution of n-butyllithium (2.5N in hexanes, 30.5 mL, 76 mmol) was added slowly at such a rate as to keep the internal temperature below 0° C. After stirring for 5 min, the solution was cooled to −20° C. and added to a solution of acetonitrile (2.37 mL, 45.3 mmol) and ethyl 3,5-difluorobenzoate (6.23 g, 36.2 mmol) in dry THF (18 mL) at such a rate as to keep the temperature below −40° C. A further 10 mL of dry THF was used to transfer the remaining lithium diisopropylamide to the reaction. The reaction was allowed to warm to ambient over 2 h before being quenched with saturated aqueous ammonium chloride solution. The reaction was extracted with ethyl acetate (×2) and the extracts discarded. The aqueous was acidified with 2N HCl and extracted with ethyl acetate. The organic extract was washed with 2N HCl and brine before being dried over MgSO4, filtered and evaporated. Purification using chromatography (silica gel, gradient 5 to 100% ethyl acetate/isohexane) gave 3-(3,5-difluorophenyl)-3-oxopropanenitrile as a yellow solid (2.82 g). the internal temperature below 0° C the solution was cooled to −20° C. the temperature below −40° C to the reaction to warm to ambient over 2 h before being quenched with saturated aqueous ammonium chloride solution The reaction was extracted with ethyl acetate (×2) extracted with ethyl acetate The organic extract was washed with 2N HCl and brine before being dried over MgSO4 filtered evaporated Purification

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

Procedure: 10.0 mL of conc. HNO3 at 0° C. was slowly treated with 20.0 mL of conc. H2SO4, then 7.6 g (40 mmol) of 3,5-difluoro-benzoic acid ethyl ester. The reaction mixture was warmed up to room temperature and stirred overnight. This mixture was poured into a beaker containing ice. The resulting mixture was extracted with ethyl acetate, washed with cold water and evaporated to produce 7.4 g (32 mmol, 80%) of 3,5-difluoro-2-nitro-benzoic acid ethyl ester. LCMS: 232 (M+1)+. This mixture was poured into a beaker containing ice The resulting mixture was extracted with ethyl acetate washed with cold water evaporated