4-(trifluoromethoxy)benzyl trichloroacetimidate:

4-(Trifluoromethoxy)benzyl Trichloroacetimidate

To a stirred suspension of NaH (60%, 127 mg, 3.45 mmol) in t-BuOMe (100 mL) was added 4-(trifluoromethoxy)benzyl alcohol 11 (5 mL, 34.5 mmol) dropwise by syringe at room temperature. After H2 evolution had ceased (about 5 min), the clear mixture was cooled to 0 °C. Cl3CCN (3.46 mL, 34.5 mmol) was added dropwise by syringe, and the resulting solution was stirred for 1 h. After warming to room temperature, the solution was concentrated in vacuo, and the residue was resuspended in heptane (100 mL) containing MeOH (0.14 mL, 3.45 mmol). After 10 min of stirring, the suspension was filtered through a thin bed of silica and washed with heptane. Concentration in vacuo affords the title compound as a yellow-orange liquid (11.4 g, 98%) that was used directly without further purification. Rf 0.3 (5% EtOAc/hexanes);

 1H NMR (501 MHz, CDCl3) δ 8.43 (s, 1H), 7.48 (d, J = 8.2 Hz, 2H), 7.24 (d, J = 8.2 Hz, 2H), 5.35 (s, 2H); 

13C NMR (126 MHz, CDCl3) δ 162.6, 149.3, 134.3, 129.4, 121.6, 121.3, 119.6, 69.9; 

IR [CH2Cl2 solution] νmax (cm−1) 3345, 2954, 1667, 1511, 1261, 1221, 1166, 1077, 998, 828, 797, 649; 

HRMS (ESI-TOF) calcd for C10H7Cl3F3NO2 334.95, found C8H6F3O 174.03.