Acetic Acid → HCID 69035105, compound

Temperature

80 °C

Vinylmagnesium bromide (40 mL of a 1.0 M THF solution, 40 mmol) was added to a dry round bottom flask under nitrogen. The solution was cooled to −10° C. and charged with meta-trifluoromethylbenzaldehyde (5.0 g, 29 mmol). The reaction was stirred for 1 h, warmed to RT and quenched with sat. NH4Cl. The mixture was extracted with EtOAC three times, and the organic extracts were dried (MgSO4) and concentrated in vacuo. The crude material was purified via flash chromatography to give 1-(3-trifluoromethylphenyl)propen-1-ol as an oil (5.0 g, 87% yield). A portion of 1-(3-trifluoromethylphenyl)-propen-1-ol (0.5 g, 2.5 mmol) was dissolved in acetone (20 mL). The resultant solution was cooled to 0° C., treated with Jones reagent (1.14 mL of a 2.6 M solution, 2.96 mmol), and stirred for 10 minutes before being quenched with the addition of isopropyl alcohol (1.5 mL). The mixture was stirred for 5 min at rt, diluted with Et2O, filtered through Celite, washed with 10% Na2SO3. The material was purified via filtration through a plug of silica gel (1:1 Et2O:hexanes as eluant) to provide the 1-(3-trifluoromethylphenyl)propenone as an oil (320 mg, 65% yield), which solidified upon standing in the freezer. 1H-NMR (300 MHz, CDCl3): δ 8.20 (s, 1H), 8.13 (d, 1H, J=7.7 Hz), 7.84 (d, 1H, J=9.0 Hz), 7.64 (t, 1H, J=7.7 Hz), 7.16 (dd, 1H, J=17.2, 10.6 Hz), 6.49 (dd, 1H, J=17.2, 1.5 Hz), 6.03 (dd, 1H, J=10.6, 1.5 Hz). (28b) The compound (±) [(1S*,2R*,4R*)-4-azido-2-(4-methylsulfanyl-benzenesulfonylmetyl)-cyclohexyl]-carbamic acid tert-butyl ester (2.36 g, 5.36 mmol, see procedure 10d above) was dissolved in 2:1 CH2Cl2/TFA and stirred at rt for 1 h before being concentrated in vacuo. The resulting residue was redissolved in 1N NaOH and this solution was extracted twice with Et2O. The extracts were combined, washed with brine, dried (MgSO4), filtered, and concentrated in vacuo. The product amine was dissolved in MeOH (40 mL), cooled to −10° C., and treated with a solution of the 1-(3-trifluoromethylphenyl)propenone (1.09 g, 5.23 mmol) in MeOH (10 mL). The reaction was stirred for 30 min at rt, diluted with EtOAc, and washed successively with sat. NaHCO3 and brine. The organic phase was dried (MgSO4), filtered, and concentrated in vacuo. The resultant residue was purified by flash chromatography to give the desired (±) 3-[(1S*,2R*,4R*)-4-azido-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexylamino]-1-(3-trifluoromethyl-phenyl)-propan-1-one (2.0 g, 69% yield). MS found: (M+H)+=541.3. (28c) To a cooled (0° C.) solution of dimethylphosphono-acetic acid tert-butyl ester (0.44 mL, 2.22 mmol) in THF (20 mL) was added sodium hydride (94 mg, 60 wt % dispersion in oil, 2.35 mmol) in one portion. The mixture was stirred for 30 minutes at 0° C. and then charged with a solution of (±) 3-[(1S*,2R*,4R*)-4-azido-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexylamino]-1-(3-trifluoromethyl-phenyl)-propan-1-one (0.75 g, 1.38 mmol) in THF. The reaction was stirred for 64 h at rt, quenched with sat. NH4Cl, and extracted twice with EtOAc. The organic extracts were combined, washed with brine, dried (Na2SO4), filtered, and concentrated in vacuo. The crude residue was purified by flash chromatography to afford diastereomerically-pure (±) E-[5-[(1S*,2R*,4R*)-4-azido-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexylamino]-3-(3-trifluoromethyl-phenyl)-pent-2-enoic acid tert-butyl ester] (0.26 g, 29% yield) and a number of impure fractions of the same compound contaminated with its Z-diastereomer. MS found: (M+H)+=639.3. (28d) The compound (±) E-[5-[(1S*,2R*,4R*)-4-azido-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexylamino]-3-(3-trifluoromethyl-phenyl)-pent-2-enoic acid tert-butyl ester] (0.26 g, 0.4 mmol) was dissolved in 2:1 CH2Cl2/TFA and stirred at rt for 1 h before being concentrated in vacuo. The residue was redissolved in CH2Cl2 and concentrated in vacuo; this procedure was repeated once. The unpurified amino acid was dissolved in CH2Cl2, and the resulting solution was sequentially charged with N, N-diisopropylethylamine (0.3 mL, 1.6 mmol), 4-dimethylaminopyridine (54 mg, 0.44 mmol), and HATU (170 mg, 0.44 mmol). The mixture was stirred for 14 h at rt, quenched with sat. NH4Cl, and extracted twice with EtOAc. The organic extracts were combined, washed with brine, dried (Na2SO4), filtered, and concentrated in vacuo. The crude residue was purified by flash chromatography to afford (±) 1-[(1S*,2R*,4R*)-4-azido-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexyl]-4-(3-trifluoromethyl-phenyl)-5,6-dihydro-1H-pyridin-2-one (0.2 g, 89% yield). The entirity of this material was dissolved in MeOH. The resultant solution was charged with 0.1 g of 10% Pd/BaSO4, and the flask was evacuated and then back-filled with hydrogen (1 atm). This procedure was repeated several times. The reaction was stirred for 12 h and then filtered. The resultant solution was concentrated in vacuo to provide (±) 1-[(1S*,2R*,4R*)-4-amino-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexyl]-4-(3-trifluoromethyl-phenyl)-5,6-dihydro-1H-pyridin-2-one (quantitative; ˜90% purity). MS found: (M+H)+=538. (28e) To a solution of (±) 1-[(1S*,2R*,4R*)-4-amino-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexyl]-4-(3-trifluoromethyl-phenyl)-5,6-dihydro-lH-pyridin-2-one (0.36 mmol) in dichloroethane (6 mL) was added acetic acid (0.1 mL, 1.8 mmol), acetone (0.08 mL, 1.1 mmol), and sodium triacetoxyborohydride (0.23 g, 1.1 mmol). The mixture was heated at 80° C. for 1 h, cooled to rt, and quenched with sat. NaHCO3, and extracted twice with EtOAc. The organic extracts were combined, washed with brine, dried (Na2SO4), filtered, and concentrated in vacuo. A portion of the crude residue was purified by reverse-phase HPLC to provide two fractions, one of which contained the title. MS found: (M+H)+=581.

1. temperaturecooled to rt
2. customquenched with sat. NaHCO3
3. extractionextracted twice with EtOAc
4. washwashed with brine
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customA portion of the crude residue was purified by reverse-phase HPLC
9. customto provide two fractions, one of which

ORD record

ord-7d955acbdb524e69938208d1c29346d8

Source dataset

uspto-grants-2008_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07338947B2