反应详情

To a solution of Intermediate 1e (1.81 g, 9.18 mmol), triphenylphosphine (4.83 g, 18.4 mmol), and triethylamine (5.12 mL, 36.7 mmol) in THF (25 mL) at 0° C., hexachloroethane (4.36 g, 18.4 mmol) was added in 2 portions at a 1 min intervals. The resulting pale brown solution was allowed to warm to RT then stirred for 2 h. The resulting yellow suspension was filtered, washing with THF (2×25 mL). The combined organics were purified using SCX-2 cartridge (washed with DCM-MeOH (1:1, 100 mL) and MeOH (50 mL), and then the product was eluted with 2M NH3 in MeOH) to give a pale yellow solid (1.60 g, 97%, contaminated with ˜2.5% Ph3P═O). 1H NMR (400 MHz, CDCl3): 1.53 (6H, d), 3.32 (1H, sept), 7.15 (1H, ddd), 7.75 (1H, ddd), 7.84 (1H, m).

1. filtrationThe resulting yellow suspension was filtered
2. washwashing with THF (2×25 mL)
3. customThe combined organics were purified
4. washwashed with DCM-MeOH (1:1, 100 mL) and MeOH (50 mL)
5. washthe product was eluted with 2M NH3 in MeOH)
6. customto give a pale yellow solid (1.60 g, 97%