反应详情

4-[(E)-methoxyimino]-pentanoic acid methyl-(5-pyridin-3-yl-[1,3,4]thiadiazol-2-yl)-amide was prepared as described in J F W Keana et al. in J. Org. Chem., 1985, 50, 2346. A suspension of O-methylhydroxylamine hydrochloride (0.065 g, 0.9 mmol), 4-oxo-pentanoic acid methyl-(5-pyridin-3-yl-[1,3,4]thiadiazol-2-yl)-amide (0.18 g, 0.6 mmol) and sodium acetate (0.076 g, 0.9 mmol) in anhydrous ethanol was refluxed under nitrogen for 14 hours, cooled, concentrated under reduced pressure and chromatographed on silica to afford the title compound as an amorphous yellow solid (0.071 g, 36%): mp 114-121° C.; 1H NMR (400 MHz, CDCl3) δ 9.15 (d, J=1.8 Hz, 1H), 8.70 (dd, J=4.8, 1.8 Hz, 1H), 8.29 (dt, J=5.9, 1.8 Hz, 1H), 7.43 (dd, J=7.7, 5.2 Hz, 1H), 3.92 (s, 3H), 3.86, 3.83 and 3.77 (all s, 1H), 2.95 (q, J=7.0 Hz, 2H), 2.71 (q, J=7.4 Hz, 2H), 2.11, 1.98 and 1.89 (all s, 3H); ESIMS m/z 320 ([M+H]+).

1. custom4-[(E)-methoxyimino]-pentanoic acid methyl-(5-pyridin-3-yl-[1,3,4]thiadiazol-2-yl)-amide was prepared
2. temperaturewas refluxed under nitrogen for 14 hours
3. temperaturecooled
4. concentrationconcentrated under reduced pressure
5. customchromatographed on silica