反应详情

A solution of diethyl [1-(4-nitrophenyl)ethyl]phosphonate (206 mg, 0.717 mmol) in THF (5 mL) at room temperature under N2, was treated portionwise with NaH (60% in mineral oil, 143 mg, 3.58 mmol). The resulting mixture was stirred for 5 min then iodomethane (0.268 mL, 4.30 mmol) was added dropwise and the mixture stirred for a further 5 h. Water (10 mL) was added slowly followed by EtOAc (20 mL). The layers were separated and the aqueous phase extracted with EtOAc (3×20 mL). The organic phases were combined, dried (MgSO4), concentrated in vacuo, and the residue purified by chromatography over silica gel eluting with 5% MeOH in dichloromethane to afford 103 mg of desired diethyl [2-(4-nitrophenyl)propan-2-yl]phosphonate (yield: 48%). 1H-NMR (CD3OD, 400 MHz): δ=1.22 (t, J=7.2 Hz, 6 H), 1.64 (s, 3 H), 1.69 (s, 3 H), 3.94-4.01 (m, 4 H), 7.78 (dd, J=2.4, 9.2 Hz, 2 H), 8.21 (dd, J=0.8, 8.8 Hz, 2 H). MS (ES+): m/z 302.11 (MH+). HPLC: tR=1.44 min (UPLC TOF, polar).

1. stirringthe mixture stirred for a further 5 h
2. customThe layers were separated
3. extractionthe aqueous phase extracted with EtOAc (3×20 mL)
4. dry with materialdried (MgSO4)
5. concentrationconcentrated in vacuo
6. customthe residue purified by chromatography over silica gel eluting with 5% MeOH in dichloromethane