2,6-Lutidine → [2-Ethyl-4-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-but-2-enyloxymethyl]-phosphonic acid

참여 물질

반응 단계

To a solution of {2-ethyl-4-[6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-but-2-enyloxymethyl}-phosphonic acid diisopropyl ester (347 mg, 0.61 mmol) in acetonitrile (5 mL) was added 2,6-lutidine (0.71 mL, 6.1 mmol) and bromotrimethylsilane (0.786 mL, 6.1 mmol). The mixture was stirred at room temperature for 3 hours, quenched with methanol (5 mL), concentrated, and partitioned between ethyl acetate and 1N HCl (aqueous). The organic layer was concentrated to give the free phosphonic acid as a colorless oil (205 mg, 70%). This material (20 mg) was dissolved in a solution of trifluoroacetic acid (0.3 mL) and dichloromethane (2.7 mL) and stirred for 30 minutes at ambient temperature. After concentration, the residue was purified by RP HPLC using a C18 column with a gradient of H2O, 0.1% TFA-acetonitrile, 0.1% TFA to provide the product, after lyophilization, as a white solid (10 mg). 1H NMR (300 MHz, CDCl3) δ 1.007 (t, 3H, J=7.5 Hz), 2.13 (s, 3H), 2.32 (q, 2H, J=7.5 Hz), 3.41 (d, 2H, J=6.3 Hz), 3.56 (d, 2H, J=9 Hz), 3.75 (s, 3H), 3.95 (s, 2H), 5.16 (s, 2H), 5.43 (t, 1H, J=6.3 Hz) ppm; 31P (121.4 MHz, CDCl3) δ 22.8 ppm; MS (m/z) 385.2 [M−H]+, 387.1 [M+H]+.

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