反应详情

To a solution in 2-[(3,5-dihydroxy-pyridine-2-carbonyl)-amino]-2-methyl-propionic acid methyl ester, 18, (0.312 g, 1.23 mmol) in MeOH (10 mL) containing diisopropylethylamine (0.214 mL, 1.23 mmol) at 0° C. under N2 is added N-phenyltrifluoromethanesulfonamide (0.439 g, 1.23 mmol). The reaction is warmed slowly to room temperature and stirred for 40 hours. The solvent is removed under reduced pressure and the crude oil which remains is purified over silica (EtOAc:heptane 1:9) to afford 0.170 g (36% yield) of the desired compound as a yellow oil. 1H NMR (250 MHz, MeOD) δ ppm 8.85 (1H, br s), 8.19 (1H, d, J=2.4 Hz), 7.46 (1 H, d, J=2.3 Hz), 3.74 (3H, s), 1.63 (6H, s). HPLC-MS: m/z 387 [M+H]+.

1. customThe solvent is removed under reduced pressure
2. customthe crude oil which remains is purified over silica (EtOAc:heptane 1:9)