Trifluoroacetic anhydride → N-[(R)-1-(5-bromo-2-fluoro-phenyl)-2-((R)-1-cyano-2,2,2-trifluoro-1-methyl-ethoxy)-1-methyl-ethyl]-2-nitro-benzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)-2-[(R)-2-(5-bromo-2-fluoro-pheyl)-2-(2-nitro-benzenesulfonylamino)-propoxy]-3,3,3-trifluoro-2-methyl-propionamide (20.83 g, 35.6 mmol) in CH2Cl2 (300 ml) was added under argon NEt3 (12.5 ml, 89 mmol) and at 0-5° C. trifluoroacetic anhydride (6.15 ml, 42.7 mmol). After stirring for 4 h at 25° C. the reaction mixture was added to a cold NaHCO3 solution and the product was extracted with CH2Cl2. Combined extracts were washed with cold 0.1 N aqueous HCl, water and saturated NaHCO3 solution, dried over MgSO4, filtered and concentrated to provide the title compound as a yellow oil, which was used as such for the next step: TLC (hexane-EtOAc 1:1): Rf=0.73; HPLC RtH5=1.364 min; ESIMS: 571, 573 [(M+NH4)+]; 1H NMR (360 MHz, CDCl3): δ 7.89 (d, 1H), 7.62 (ddd, 1H), 7.57 (ddd, 1H), 7.52 (m, 2H), 7.29 (m, 1H), 6.58 (dd, 1H), 6.19 (s, 1H), 4.17 (s, 2H), 1.81 (s, 3H), 1.72 (s, 3H).

Provenance & Evidence