Methyl Nicotinate → Dimethyl [2-oxo-2-(pyridin-3-yl)ethyl]phosphonate

関与物質

反応条件

反応手順

A solution of n-butyl lithium in hexanes (9.0 mL, 1.6 M, 14 mmol) was added over 10 min. to a solution of dimethyl methylphosphonate (1.50 mL, 1.72 g, 13.8 mmol) in THF (60 mL) cooled in a dry ice/isopropanol bath. After 30 min., a solution of methyl nicotinate (757 mg, 5.52 mmol) in THF (6 mL) was added over 2 min. The solution was stirred in the cooling bath for 45 min. before being allowed to warm to 0° C. over 1 h. The reaction was quenched with saturated aq. NH4Cl (50 mL) and then partitioned between saturated aq. brine (50 mL) and methylene chloride (200 mL). The aq. layer was extracted with methylene chloride (2×100 mL). The combined organic layers were dried (sodium sulfate) decanted, and evaporated. Purification by flash column chromatography on silica gel, eluting with ethyl acetate followed by 97:3 v/v methylene chloride/CH3OH, gave material containing some residual impurity Further purification by flash column chromatography on silica gel, eluting with 50:50:5 v/v/v to 50:50:10 v/v/v toluene/ethyl acetate /CH3OH gave 1.15 g of the title compound. For the title compound: 1H NMR (500 MHz, CDCl3) δ9.26-9.20 (bs,1H), 8.83 (d, J=4, 1H), 8.34 (dt, J=8, 2, 1H), 7.70 (dd, J=8, 4, 1H), 3.82 (d, J=11, 6H), 3.67 (d, J=24, 2H).

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