4,4,4-trifluoro-2-methylbutanoic acid

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

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

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

Procedure: To sodium hexamethyldisilazane (0.945 M in tetrahydrofuran) (667 mL, 0.63 mol) in tetrahydrofuran (0.9 L) at -78° C., under nitrogen, was added a solution of ethyl 4,4,4-trifluorobutyrate (90.6 mL) in tetrahydrofuran (100 mL). After stirring for 1.5 hour, to the vigorously stirred mixture was added methyl iodide (112 mL) as fast as possible. The reaction was warmed with a 0° C. bath for 2 hours. Methanol (1 L) and 1N lithium hydroxide (1.2 L) were added and stirring continued for 48 hours. The mixture was acidified with 2N hydrochloric acid and extracted with ethyl acetate. The combined organic phase was washed (brine), dried (MgSO4), and evaporated at 30° C. After combination with product from separate conversions of ethyl 4,4,4-trifluorobutyrate (97.79 g), distillation afforded 2-methyl-4,4,4-trifluorobutyric acid (173.24 g, 96%) as a brown solid-liquid contaminated with 4,4,4-trifluorobutyric acid and 2,2-dimethyl-4,4,4-trifluorobutyric acid; bp 48.0°-108° C. (9,900 Pa); GLC: tR =6.1 min. stirring continued for 48 hours extracted with ethyl acetate The combined organic phase was washed (brine) dried (MgSO4) evaporated at 30° C After combination with product from separate conversions of ethyl 4,4,4-trifluorobutyrate (97.79 g), distillation

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

Procedure: To sodium hexamethyldisilazane (0.945M in tetrahydrofuran) (667 mL, 0.63 mol) in tetrahydrofuran (0.9 L) at -78° C., under nitrogen, was added a solution of ethyl 4,4,4-trifluorobutyrate (90.6 mL) in tetrahydrofuran (100 mL). After stirring for 1.5 hour, to the vigorously stirred mixture was added methyl iodide (112 mL) as fast as possible. The reaction was warmed with a 0° C. bath for 2 hours. Methanol (1 L) and 1N lithium hydroxide (1.2 L) were added and stirring continued for 48 hours. The mixture was acidified with 2N hydrochloric acid and extracted with ethyl acetate. The combined organic phase was washed (brine), dried (MgSO4), and evaporated at 30° C. After combination with product from separate conversions of ethyl 4,4,4-trifluorobutyrate (97.79 g), distillation afforded 2-methyl-4,4,4-trifluorobutyric acid (173.24 g, 96%) as a brown solid-liquid contaminated with 4,4,4-trifluorobutyric acid and 2,2-dimethyl-4,4,4-trifluorobutyric acid; bp 48.0°-108° C. (9,900 Pa); GLC: tR =6.1 min. stirring continued for 48 hours extracted with ethyl acetate The combined organic phase was washed (brine) dried (MgSO4) evaporated at 30° C After combination with product from separate conversions of ethyl 4,4,4-trifluorobutyrate (97.79 g), distillation

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

Procedure: A mixture of TFA salt of 6-piperazin-1-yl-pyridazine-3-carboxylic acid (3-methylbutyl)amide (100 mg, 0.25 mmol), 4,4,4-trifluoro-2-methylbutyric acid (47.8 mg, 0.31 mmol), 1,8-diazabicylco[5.4.0]undec-7-ene (77.8 mg, 0.51 mmol) and 1-hydroxy-benozotriazole hydrate (41.4 mg, 0.31 mmol) in DMF (2 mL) was stirred at ambient temperature for 15 minutes. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide (47.6 mg, 0.31 mmol) was added to this solution. The reaction mixture was stirred at ambient temperature overnight and then diluted with ethyl acetate (50 mL) and washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL). The organic extract was dried over anhydrous Na2SO4, concentrated, and then purified by column chromatography eluted with hexanesethyl acetate (1:2). The product was obtained as a white flaky solid (80 mg, 75% yield). 1H NMR (300 MHz, CDCl3) δ 8.07, 7.85, 7.01, 3.60-4.00, 3.50, 3.15, 2.80, 2.21, 1.70, 1.50, 1.25, 0.95. MS (ES+) m/z 41 (M+1). The reaction mixture was stirred at ambient temperature overnight washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL) The organic extract was dried over anhydrous Na2SO4 concentrated purified by column chromatography eluted with hexanesethyl acetate (1:2)

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

Procedure: A mixture of TFA salt of 6-piperazin-1-yl-pyridazine-3-carboxylic acid (3-methylbutyl)amide (100 mg, 0.25 mmol), 4,4,4-trifluoro-2-methylbutyric acid (47.8 mg, 0.31 mmol), 1,8-diazabicylco[5.4.0]undec-7-ene (77.8 mg, 0.51 mmol) and 1-hydroxy-benozotriazole hydrate (41.4 mg, 0.31 mmol) in DMF (2 mL) was stirred at ambient temperature for 15 minutes. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide (47.6 mg, 0.31 mmol) was added to this solution. The reaction mixture was stirred at ambient temperature overnight and then diluted with ethyl acetate (50 mL) and washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL). The organic extract was dried over anhydrous Na2SO4, concentrated, and then purified by column chromatography eluted with hexanesethyl acetate (1:2). The product was obtained as a white flaky solid (80 mg, 75% yield). 1H NMR (300 MHz, CDCl3) δ 8.07, 7.85, 7.01, 3.60-4.00, 3.50, 3.15, 2.80, 2.21, 1.70, 1.50, 1.25, 0.95. MS (ES+) m/z 41 (M+1). The reaction mixture was stirred at ambient temperature overnight washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL) The organic extract was dried over anhydrous Na2SO4 concentrated purified by column chromatography eluted with hexanesethyl acetate (1:2)

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

Procedure: A mixture of TFA salt of 6-piperazin-1-yl-pyridazine-3-carboxylic acid (3-methylbutyl)amide (100 mg, 0.25 mmol), 4,4,4-trifluoro-2-methylbutyric acid (47.8 mg, 0.31 mmol), 1,8-diazabicylco[5.4.0]undec-7-ene (77.8 mg, 0.51 mmol) and 1-hydroxy-benozotriazole hydrate (41.4 mg, 0.31 mmol) in DMF (2 mL) was stirred at ambient temperature for 15 minutes. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide (47.6 mg, 0.31 mmol) was added to this solution. The reaction mixture was stirred at ambient temperature overnight and then diluted with ethyl acetate (50 mL) and washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL). The organic extract was dried over anhydrous Na2SO4, concentrated, and then purified by column chromatography eluted with hexanesethyl acetate (1:2). The product was obtained as a white flaky solid (80 mg, 75% yield). 1H NMR (300 MHz, CDCl3) δ 8.07, 7.85, 7.01, 3.60-4.00, 3.50, 3.15, 2.80, 2.21, 1.70, 1.50, 1.25, 0.95. MS (ES+) m/z 41 (M+1). The reaction mixture was stirred at ambient temperature overnight washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL) The organic extract was dried over anhydrous Na2SO4 concentrated purified by column chromatography eluted with hexanesethyl acetate (1:2)

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

Procedure: To a solution of 1-(pyridin-3-yl)-1H-pyrazol-4-amine (0.150 g, 0.93 mmol) in dichloroethane (1.8 ml) was added 4,4,4-trifluoro-2-methylbutanoic acid (0.14 g, 0.93 mmol) and 4-N,N-dimethylaminopyridine (0.23 g, 1.87 mmol) followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.36 g, 1.87 mmol). The reaction stirred at room temperature overnight. The reaction mixture was concentrated and the crude product was purified by silica gel chromatography eluting with 0-5% MeOH/dichloromethane to give a white solid (0.15 g, 55%); mp 140-145° C.; 1H NMR (400 MHz, CDCl3) δ 9.00 (d, J=2.4 Hz, 1H), 8.62-8.47 (m, 2H), 8.01 (ddd, J=8.3, 2.7, 1.5 Hz, 1H), 7.68 (s, 1H), 7.53 (bs, 1H), 7.40 (ddd, J=8.3, 4.8, 0.6 Hz, 1H), 2.92-2.61 (m, 2H), 2.32-2.05 (m, 1H), 1.38 (d, J=6.6 Hz, 3H); ESIMS m/z 300 ([M+2]). The reaction mixture was concentrated the crude product was purified by silica gel chromatography eluting with 0-5% MeOH/dichloromethane

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

Procedure: A mixture of TFA salt of 6-piperazin-1-yl-pyridazine-3-carboxylic acid (3-methylbutyl)amide (100 mg, 0.25 mmol), 4,4,4-trifluoro-2-methylbutyric acid (47.8 mg, 0.31 mmol), 1,8-diazabicylco[5.4.0]undec-7-ene (77.8 mg, 0.51 mmol) and 1-hydroxy-benozotriazole hydrate (41.4 mg, 0.31 mmol) in DMF (2 mL) was stirred at ambient temperature for 15 minutes. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide (47.6 mg, 0.31 mmol) was added to this solution. The reaction mixture was stirred at ambient temperature overnight and then diluted with ethyl acetate (50 mL) and washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL). The organic extract was dried over anhydrous Na2SO4, concentrated, and then purified by column chromatography eluted with hexanesethyl acetate (1:2). The product was obtained as a white flaky solid (80 mg, 75% yield). 1H NMR (300 MHz, CDCl3) δ 8.07, 7.85, 7.01, 3.60-4.00, 3.50, 3.15, 2.80, 2.21, 1.70, 1.50, 1.25, 0.95. MS (ES+) m/z 41 (M+1). The reaction mixture was stirred at ambient temperature overnight washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL) The organic extract was dried over anhydrous Na2SO4 concentrated purified by column chromatography eluted with hexanesethyl acetate (1:2)

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

Procedure: A mixture of TFA salt of 6-piperazin-1-yl-pyridazine-3-carboxylic acid (3-methylbutyl)amide (100 mg, 0.25 mmol), 4,4,4-trifluoro-2-methylbutyric acid (47.8 mg, 0.31 mmol), 1,8-diazabicylco[5.4.0]undec-7-ene (77.8 mg, 0.51 mmol) and 1-hydroxy-benozotriazole hydrate (41.4 mg, 0.31 mmol) in DMF (2 mL) was stirred at ambient temperature for 15 minutes. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide (47.6 mg, 0.31 mmol) was added to this solution. The reaction mixture was stirred at ambient temperature overnight and then diluted with ethyl acetate (50 mL) and washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL). The organic extract was dried over anhydrous Na2SO4, concentrated, and then purified by column chromatography eluted with hexanesethyl acetate (1:2). The product was obtained as a white flaky solid (80 mg, 75% yield). 1H NMR (300 MHz, CDCl3) δ 8.07, 7.85, 7.01, 3.60-4.00, 3.50, 3.15, 2.80, 2.21, 1.70, 1.50, 1.25, 0.95. MS (ES+) m/z 41 (M+1). The reaction mixture was stirred at ambient temperature overnight washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL) The organic extract was dried over anhydrous Na2SO4 concentrated purified by column chromatography eluted with hexanesethyl acetate (1:2)

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

Procedure: A mixture of TFA salt of 6-piperazin-1-yl-pyridazine-3-carboxylic acid (3-methylbutyl)amide (100 mg, 0.25 mmol), 4,4,4-trifluoro-2-methylbutyric acid (47.8 mg, 0.31 mmol), 1,8-diazabicylco[5.4.0]undec-7-ene (77.8 mg, 0.51 mmol) and 1-hydroxy-benozotriazole hydrate (41.4 mg, 0.31 mmol) in DMF (2 mL) was stirred at ambient temperature for 15 minutes. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide (47.6 mg, 0.31 mmol) was added to this solution. The reaction mixture was stirred at ambient temperature overnight and then diluted with ethyl acetate (50 mL) and washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL). The organic extract was dried over anhydrous Na2SO4, concentrated, and then purified by column chromatography eluted with hexanes:ethyl acetate (1:2). The product was obtained as a white flaky solid (80 mg, 75% yield). 1H NMR (300 MHz, CDCl3) δ 8.07, 7.85, 7.01, 3.60-4.00, 3.50, 3.15, 2.80, 2.21, 1.70, 1.50, 1.25, 0.95. MS (ES+) m/z 416 (M+1). The reaction mixture was stirred at ambient temperature overnight washed with aqueous saturated NaHCO3 (2×20 mL) and finally with brine (2×20 mL) The organic extract was dried over anhydrous Na2SO4 concentrated purified by column chromatography eluted with hexanes:ethyl acetate (1:2)

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

Procedure: A solution of 2-methyl-4,4,4-trifluorobutyric acid (108 mg, 0.692 mmol) and 1,1′-carbonyldiimidazole (101 mg, 0.623 mmol) in DMF (1 ml) was stirred at room temperature under a nitrogen atmosphere. After 30 min, compound 13-A (100 mg, 0.254 mmol) was added and the solution stirred overnight. DMF was removed in vacuo and the solid was redissolved in CH3CN (4 ml). Product was purified by Gilson reverse phase chromatography eluting with a 10-90% CH3CN (0.1% TFA)/water (0.1% TFA) gradient. Solvent was removed in vacuo and the product free based from methylene chloride and saturated aqueous sodium bicarbonate. The organic layer was dried over MgSO4 and the solvent removed to yield 13-B as a white solid. MS (ESI+)=532.18 (M+1). DMF was removed in vacuo the solid was redissolved in CH3CN (4 ml) Product was purified by Gilson reverse phase chromatography eluting with a 10-90% CH3CN (0.1% TFA)/water (0.1% TFA) gradient Solvent was removed in vacuo The organic layer was dried over MgSO4 the solvent removed