methyl 2,2,3,3,3-pentafluoropropanoate

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

Conditions: temp:-73.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-iodopyrazole (3.0 g) in tetrahydrofuran (80 ml) at -80° C. under an atmosphere of nitrogen was added, at such a rate that the temperature of the reaction mixture did not exceed -73° C., n-butyllithium (2.78 ml of a 2.5M solution in hexanes). The mixture was stirred at -73° C. for 10 minutes and then a solution of methyl pentafluoropropionate (0.89 ml) in tetrahydrofuran (5 ml) was then added at such a rate that the temperature of the reaction mixture did not exceed -75° C. Upon completion of the addition the mixture allowed to warm to room temperature over a period of 1.5 hours. Water (100 ml) was added and the mixture extracted twice with ethyl acetate (80 ml). The combined organic layers were dried (Na2SO4) and evaporated to give a pale yellow solid which was purified by column chromatography on silica gel (150 g) eluted with dichloromethane:hexane (9:1). Combination and evaporation of suitable fractions gave a yellow oil which was further purified by column chromatography on silica gel (50 g) eluted with dichloromethane:hexane (9:1). Combination and evaporation of suitable fractions gave the title compound as a white solid, m.p. 120° C. did not exceed -73° C. did not exceed -75° C Upon completion of the addition the mixture to warm to room temperature over a period of 1.5 hours the mixture extracted twice with ethyl acetate (80 ml) The combined organic layers were dried (Na2SO4) evaporated to give a pale yellow solid which was purified by column chromatography on silica gel (150 g) eluted with dichloromethane:hexane (9:1) Combination and evaporation of suitable fractions gave a yellow oil which was further purified by column chromatography on silica gel (50 g) eluted with dichloromethane:hexane (9:1) Combination and evaporation of suitable fractions

Conditions: temp:-73.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-iodopyrazole (3.0 g) in tetrahydrofuran (80 ml) at -80° C. under an atmosphere of nitrogen was added, at such a rate that the temperature of the reaction mixture did not exceed -73° C., n-butyllithium (2.78 ml of a 2.5M solution in hexanes). The mixture was stirred at -73° C. for 10 minutes and then a solution of methyl pentafluoropropionate (0.89 ml) in tetrahydrofuran (5 ml) was then added at such a rate that the temperature of the reaction mixture did not exceed -75° C. Upon completion of the addition the mixture allowed to warm to room temperature over a period of 1.5 hours. Water (100 ml) was added and the mixture extracted twice with ethyl acetate (80 ml). The combined organic layers were dried (Na2SO4) and evaporated to give a pale yellow solid which was purified by column chromatography on silica gel (150 g) eluted with dichloromethane:hexane (9:1). Combination and evaporation of suitable fractions gave a yellow oil which was further purified by column chromatography on silica gel (50 g) eluted with dichloromethane:hexane (9:1). Combination and evaporation of suitable fractions gave the title compound as a white solid, m.p. 120° C. did not exceed -73° C. did not exceed -75° C Upon completion of the addition the mixture to warm to room temperature over a period of 1.5 hours the mixture extracted twice with ethyl acetate (80 ml) The combined organic layers were dried (Na2SO4) evaporated to give a pale yellow solid which was purified by column chromatography on silica gel (150 g) eluted with dichloromethane:hexane (9:1) Combination and evaporation of suitable fractions gave a yellow oil which was further purified by column chromatography on silica gel (50 g) eluted with dichloromethane:hexane (9:1) Combination and evaporation of suitable fractions

Conditions: temp:-73.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-iodopyrazole (3.0 g) in tetrahydrofuran (80 ml) at -80° C. under an atmosphere of nitrogen was added, at such a rate that the temperature of the reaction mixture did not exceed -73° C., n-butyllithium (2.78 ml of a 2.5M solution in hexanes). The mixture was stirred at -73° C. for 10 minutes and then a solution of methyl pentafluoropropionate (0.89 ml) in tetrahydrofuran (5 ml) was then added at such a rate that the temperature of the reaction mixture did not exceed -75° C. Upon completion of the addition the mixture allowed to warm to room temperature over a period of 1.5 hours. Water (100 ml) was added and the mixture extracted twice with ethyl acetate (80 ml). The combined organic layers were dried (Na2SO4) and evaporated to give a pale yellow solid which was purified by column chromatography on silica gel (150 g) eluted with dichloromethane:hexane (9:1). Combination and evaporation of suitable fractions gave a yellow oil which was further purified by column chromatography on silica gel (50 g) eluted with dichloromethane:hexane (9:1). Combination and evaporation of suitable fractions gave the title compound as a white solid, m.p. 120° C. did not exceed -73° C. did not exceed -75° C Upon completion of the addition the mixture to warm to room temperature over a period of 1.5 hours the mixture extracted twice with ethyl acetate (80 ml) The combined organic layers were dried (Na2SO4) evaporated to give a pale yellow solid which was purified by column chromatography on silica gel (150 g) eluted with dichloromethane:hexane (9:1) Combination and evaporation of suitable fractions gave a yellow oil which was further purified by column chromatography on silica gel (50 g) eluted with dichloromethane:hexane (9:1) Combination and evaporation of suitable fractions

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

Procedure: The procedure of Example 1 was followed using methyl perfluoropropionate (3 mL, 23.4 mmol), sodium trimethylsilanolate (2.63 g, 23.4 mmol), dry methylene chloride (100 mL), and a 1 h reaction time. Sodium perfluoropropionate (4.0 g, 92% yield) was obtained as a white solid: 1H NMR (D2O) δ -82.4 (t, J=2 Hz, CF3, 3F), -120.1 ppm (q, J=2 Hz, CF2, 2F). a 1 h reaction time

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

Procedure: The procedure of Example 1 was followed using methyl perfluoropropionate (3 mL, 23.4 mmol), sodium trimethylsilanolate (2.63 g, 23.4 mmol), dry methylene chloride (100 mL), and a 1 h reaction time. Sodium perfluoropropionate (4.0 g, 92% yield) was obtained as a white solid: 1H NMR (D2O) δ -82.4 (t, J=2 Hz, CF3, 3F), -120.1 ppm (q, J=2 Hz, CF2, 2F). a 1 h reaction time

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

Procedure: A solution of 39 g (388 mmol) of N,N-diisopropylamine in 500 ml of tetrahydrofuran is admixed at −5° C. with 232 ml (371 mmol) of a 1.6M solution of n-butyllithium in hexane. The solution is stirred for 30 minutes at 0° C. and then cooled to −78° C. 18.5 g (337 mmol) of n-propionitrile are then added dropwise. When addition is complete, the solution is stirred for 15 minutes. 30 g (169 mmol) of methyl pentafluoropropanoate are then slowly added. When addition is complete, the reaction mixture is stirred for a further 45 min at −78° C. The mixture is then heated to room temperature and stirred for one hour at room temperature. The reaction mixture is cooled to 0° C. and admixed with 700 ml of water. The pH of the solution is adjusted to 1 with conc. hydrochloric acid. The aqueous phase is extracted with ethyl acetate and the combined organic phases are dried over magnesium sulphate and concentrated by evaporation under reduced pressure on a rotary evaporator. The residue is dissolved in 200 ml of ethanol and admixed with 10.5 g (224 mmol) of methylhydrazine and 16 ml of conc. hydrochloric acid. The mixture is heated under reflux for five hours. The ethanol is removed under reduced pressure on a rotary evaporator and the pH of the aqueous phase is adjusted to 14. The aqueous phase is extracted several times with dichloromethane. The combined organic phases are dried over magnesium sulphate and concentrated by evaporation under reduced pressure on a rotary evaporator. This gives 13.0 g of 1,4-dimethyl-3-(pentafluoroethyl)-1H-pyrazole-5-amine (34%). cooled to −78° C When addition the solution is stirred for 15 minutes When addition the reaction mixture is stirred for a further 45 min at −78° C The mixture is then heated to room temperature stirred for one hour at room temperature The reaction mixture is cooled to 0° C. The aqueous phase is extracted with ethyl acetate the combined organic phases are dried over magnesium sulphate concentrated by evaporation under reduced pressure on a rotary evaporator The residue is dissolved in 200 ml of ethanol The mixture is heated under reflux for five hours The ethanol is removed under reduced pressure on a rotary evaporator The aqueous phase is extracted several times with dichloromethane The combined organic phases are dried over magnesium sulphate concentrated by evaporation under reduced pressure on a rotary evaporator

Conditions: temp:-73.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-iodopyrazole (3.0 g) in tetrahydrofuran (80 ml) at -80° C. under an atmosphere of nitrogen was added, at such a rate that the temperature of the reaction mixture did not exceed -73° C., n-butyllithium (2.78 ml of a 2.5M solution in hexanes). The mixture was stirred at -73° C. for 10 minutes and then a solution of methyl pentafluoropropionate (0.89 ml) in tetrahydrofuran (5 ml) was then added at such a rate that the temperature of the reaction mixture did not exceed -75° C. Upon completion of the addition the mixture allowed to warm to room temperature over a period of 1.5 hours. Water (100 ml) was added and the mixture extracted twice with ethyl acetate (80 ml). The combined organic layers were dried (Na2SO4) and evaporated to give a pale yellow solid which was purified by column chromatography on silica gel (150 g) eluted with dichloromethane:hexane (9:1). Combination and evaporation of suitable fractions gave a yellow oil which was further purified by column chromatography on silica gel (50 g) eluted with dichloromethane:hexane (9:1). Combination and evaporation of suitable fractions gave the title compound as a white solid, m.p. 120° C. did not exceed -73° C. did not exceed -75° C Upon completion of the addition the mixture to warm to room temperature over a period of 1.5 hours the mixture extracted twice with ethyl acetate (80 ml) The combined organic layers were dried (Na2SO4) evaporated to give a pale yellow solid which was purified by column chromatography on silica gel (150 g) eluted with dichloromethane:hexane (9:1) Combination and evaporation of suitable fractions gave a yellow oil which was further purified by column chromatography on silica gel (50 g) eluted with dichloromethane:hexane (9:1) Combination and evaporation of suitable fractions

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

Procedure: The procedure of Example 1 was followed using methyl perfluoropropionate (3 mL, 23.4 mmol), sodium trimethylsilanolate (2.63 g, 23.4 mmol), dry methylene chloride (100 mL), and a 1 h reaction time. Sodium perfluoropropionate (4.0 g, 92% yield) was obtained as a white solid: 1H NMR (D2O) δ -82.4 (t, J=2 Hz, CF3, 3F), -120.1 ppm (q, J=2 Hz, CF2, 2F). a 1 h reaction time