反应详情

To a solution of tetraethyl methylenebisphosphonate (3.00 g, 10.4 mmol) in dry DMF (9 mL) was added NaH (60% suspension in mineral oil, 0.46 g, 11.5 mmol) portionwise. The resulting slurry was stirred for 30 min at room temperature, after which t-butyl bromoacetate (1.7 mL, 11.5 mmol) was quickly added neat. The reaction mixture was stirred for 1 h and quenched by adding 2 mL of a saturated solution of NH4Cl. The reaction mixture was evaporated and purified by flash chromatography on silica gel eluting with 5% methanol/ethyl acetate to give pure 40 (2.1 g, 50%) as a clear colourless oil. 1H NMR (400 MHz, CDCl3) δ 1.33 (bt, J=7.0, 12H), 1.46 (s, 9H), 2H), 2.76 (dt, J=16.0, 6.1, 2H), 3.07 (tt, J=24.0, 6.1, 1H), 4.10-4.25 (m, 8H).

1. stirringThe reaction mixture was stirred for 1 h
2. customquenched
3. additionby adding 2 mL of a saturated solution of NH4Cl
4. customThe reaction mixture was evaporated
5. custompurified by flash chromatography on silica gel eluting with 5% methanol/ethyl acetate