ethyl 2-amino-4,4,4-trifluoro-3-(trifluoromethyl)butanoate

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: A solution of lithium borohydride (2M THF, 19.8 mL) was added to a solution of 2-amino-4,4,4-trifluoro-3-trifluoromethyl-butyric acid ethyl ester (5 g, 19.8 mmol), prepared as described (J. Med Chem. 1981, 24, 1043-1047), in THF (80 mL) at 25° C. and was stirred for 4 h. 2M HCl was added to the reaction mixture very carefully until a pH less than 2. The organic solvent was removed in vacuo and the aqueous layer was neutralized with sat NaHCO3 until pH=7. The aqueous layer was extracted with EtOAc (2×50 mL) and the organic extracts were dried over Na2SO4 and concentrated to provide 3,3,3-trifluoro-2-(trifluoromethyl)-1-(hydroxymethyl)propylamine as a yellow oil (3.2 g, 77% yield). The crude oil was of sufficient purity to utilize in the subsequent reaction. prepared The organic solvent was removed in vacuo The aqueous layer was extracted with EtOAc (2×50 mL) the organic extracts were dried over Na2SO4 concentrated

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of ethyl 4,4,4,4′,4′,4′-hexafluoro-dl-valinate (1.64 g, 6.48 mmol), prepared as described (J. Med Chem. 1981, 24, 1043-1047), in CH2Cl2 (10 mL) was stirred under N2 atmosphere at 25° C. Pyridine (0.81 mL, 10.04 mmol) was added dropwise followed by 5-bromothiophene-2-sulfonyl chloride (2.034 g, 7.77 mmol) in one portion and the resulting solution stirred for 19 h at 25° C. After this time period, the reaction was complete by TLC (1:4 EtOAc-hexane). After quenching with water (2.0 mL), the mixture was diluted with CH2Cl2 (40 mL). The organic layer was washed sequentially with 1N aqueous HCl (20 mL), saturated aqueous NaHCO3 (20 mL) and brine (15 mL), dried over MgSO4, filtered, and concentrated to obtain a crude oil (3.3 g). The crude product was purified by the Biotage Flash™ 40 chromatography system, eluent: 1:6 EtOAc-hexanes, to afford ethyl N-[(5-bromothien-2-yl)sulfonyl]-4,4,4,4′,4′,4′-hexafluoro-dl-valinate as a white solid (2.40 g, 80.0%). Mass Spectrum (−ESI): 477 (M−H)−. After quenching with water (2.0 mL) the mixture was diluted with CH2Cl2 (40 mL) The organic layer was washed sequentially with 1N aqueous HCl (20 mL), saturated aqueous NaHCO3 (20 mL) and brine (15 mL) dried over MgSO4 filtered concentrated to obtain a crude oil (3.3 g) The crude product was purified by the Biotage Flash™ 40 chromatography system, eluent

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 3,4,5-trifluorobenzenesulfonyl chloride (0.348 mL, 2.50 mmol) in CH2Cl2 (5 mL) was added to a solution of 2-amino-4,4,4-trifluoro-3-trifluoromethyl-butyric acid ethyl ester (0.4 g, 1.67 mmol) prepared as described (J. Med Chem. 1981, 24, 1043-1047), and pyridine (0.27 mL, 3.34 mmol) in CH2Cl2 (5 mL) at 0° C. and allowed to warm to 25° C. for 19 h. The solution was washed with 1M HCl (1 mL), brine (1 mL), dried over Na2SO4 and concentrated. The crude solid was purified by Biotage Flash™ chromatography, eluting with EtOAc/hexanes (1:4), to give 4,4,4-trifluoro-2-(3,4,5-trifluoro-benzenesulfonylamino)-3-trifluoromethyl-butyric acid ethyl ester (0.63 g, 85%) as a white solid. Mass Spectrum (+ESI): 448 [M+H]+. prepared at 0° C. The solution was washed with 1M HCl (1 mL), brine (1 mL) dried over Na2SO4 concentrated The crude solid was purified by Biotage Flash™ chromatography eluting with EtOAc/hexanes (1:4)

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

Procedure: To a vial containing a solution of 4-fluoro-3-methylbenzenesulfonyl chloride (50 mg, 0.24 mmol) and 2-amino-4,4,4-trifluoro-3-trifluoromethyl-butyric acid ethyl ester (61 mg, 0.24 mmol) in anhydrous dichloroethane (1 mL) was added pyridine (58 μL, 0.719 mmol). The vial was capped and shaken for 18 h. The solvent was removed in vacuo and the residue transferred to a separatory funnel with EtOAc (100 mL) and washed with distilled water (100 mL×2). The organic layer was removed and the combined aqueous washings were extracted with EtOAc (100 mL×2). The organic extracts were combined, washed with brine (100 mL), dried (MgSO4), filtered, and evaporated to give a white solid (66 mg). This material was purified by Gilson RP-HPLC (column YMC Combiprep 50×20 mm, gradient 10-100% CH3CN: H2O) to afford a white solid (29 mg, 28%). Mass Spectrum (−ESI): 424 [M−H]−. The vial was capped The solvent was removed in vacuo the residue transferred to a separatory funnel with EtOAc (100 mL) washed with distilled water (100 mL×2) The organic layer was removed the combined aqueous washings were extracted with EtOAc (100 mL×2) washed with brine (100 mL) dried (MgSO4) filtered evaporated

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

Procedure: To a vial containing a solution of 4-chloro-3-fluorobenzenesulfonyl chloride (181 mg, 0.79 mmol) and 2-amino-4,4,4-trifluoro-3-trifluoromethyl-butyric acid ethyl ester (200 mg, 0.79 mmol) in anhydrous dichloroethane (3 mL) was added pyridine (192 μL). The vial was capped and shaken for 18 h. The solvent was removed in vacuo and the residue transferred to a separatory funnel with EtOAc (100 mL) and washed with distilled water (100 mL×2). The organic layer was removed and the combined aqueous washings were extracted with EtOAc (100 mL×2). The organic extracts were combined, washed with brine (100 mL), dried (MgSO4), filtered, and evaporated to give a yellow solid (220 mg). This material was adsorbed onto silica gel and purified by column chromatography, eluent: HCCl3, to afford a white solid (186 mg, 53%). Mass Spectrum (+ESI): 446 [M−H]+. The vial was capped The solvent was removed in vacuo the residue transferred to a separatory funnel with EtOAc (100 mL) washed with distilled water (100 mL×2) The organic layer was removed the combined aqueous washings were extracted with EtOAc (100 mL×2) washed with brine (100 mL) dried (MgSO4) filtered evaporated

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

Procedure: To a solution of 3,5-difluoro-benzenesulfonyl chloride (252 mg, 1.19 mmol) and 2-amino-4,4,4-trifluoro-3-trifluoromethyl-butyric acid ethyl ester (300 mg, 1.19 mmol) in CH2Cl2 (7 mL) was added anhydrous pyridine (144 μL, 1.77 mmol, 1.50 equiv.) and the vial capped and shaken for 72 h. The reaction solution was transferred to a separatory funnel with CH2Cl2 (100 mL), washed with 1M citric acid solution (100 mL), water (50 mL×4), brine (100 mL), dried (MgSO4), filtered and evaporated to give a white solid (300 mg, 59%). Mass Spectrum (−ESI): 427.8 [M−H]− the vial capped washed with 1M citric acid solution (100 mL), water (50 mL×4), brine (100 mL) dried (MgSO4) filtered evaporated

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

Procedure: A solution of lithium borohydride (2M THF, 19.8 mL) was added to a solution of 2-amino-4,4,4-trifluoro-3-trifluoromethyl-butyric acid ethyl ester (5 g, 19.8 mmol), prepared as described (J. Med Chem. 1981, 24, 1043-1047), in THF (80 mL) at 25° C. and was stirred for 4 h. 2M HCl was added to the reaction mixture very carefully until a pH less than 2. The organic solvent was removed in vacuo and the aqueous layer was neutralized with sat NaHCO3 until pH=7. The aqueous layer was extracted with EtOAc (2×50 mL) and the organic extracts were dried over Na2SO4 and concentrated to provide 3,3,3-trifluoro-2-(trifluoromethyl)-1-(hydroxymethyl)propylamine as a yellow oil (3.2 g, 77% yield). The crude oil was of sufficient purity to utilize in the subsequent reaction. prepared The organic solvent was removed in vacuo The aqueous layer was extracted with EtOAc (2×50 mL) the organic extracts were dried over Na2SO4 concentrated

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of ethyl 4,4,4,4′,4′,4′-hexafluoro-dl-valinate (1.64 g, 6.48 mmol), prepared as described (J. Med Chem. 1981, 24, 1043-1047), in CH2Cl2 (10 mL) was stirred under N2 atmosphere at 25° C. Pyridine (0.81 mL, 10.04 mmol) was added dropwise followed by 5-bromothiophene-2-sulfonyl chloride (2.034 g, 7.77 mmol) in one portion and the resulting solution stirred for 19 h at 25° C. After this time period, the reaction was complete by TLC (1:4 EtOAc-hexane). After quenching with water (2.0 mL), the mixture was diluted with CH2Cl2 (40 mL). The organic layer washed sequentially with 1N aqueous HCl (20 mL), saturated aqueous NaHCO3 (20 mL) and brine (15 mL), dried over MgSO4, filtered, and concentrated to obtain a crude oil (3.3 g). The crude product was purified by the Biotage Flash™ 40 chromatography system, eluent: 1:6 EtOAc-hexanes, to afford ethyl N-[(5-bromothien-2-yl)sulfonyl]-4,4,4,4′,4′,4′-hexafluoro-dl-valinate as a white solid (2.40 g, 80.0%). Mass Spectrum (−ESI): 477 (M−H)−. After quenching with water (2.0 mL) the mixture was diluted with CH2Cl2 (40 mL) The organic layer washed sequentially with 1N aqueous HCl (20 mL), saturated aqueous NaHCO3 (20 mL) and brine (15 mL) dried over MgSO4 filtered concentrated to obtain a crude oil (3.3 g) The crude product was purified by the Biotage Flash™ 40 chromatography system, eluent