反应详情

温度

65 °C

To 4-(4-acetylphenyl)-1,2,4-triazolidine-3,5-dione (500 mg, 2.281 mmol) in ethanol (6.91 mL) was added O-benzylhydroxylamine hydrochloride (728 mg, 4.56 mmol) and HCl 4N in dioxane (0.277 mL, 9.12 mmol). The mixture was stirred at 65° C. for 1 hour, filtered, and then concentrated in vacuo. Saturated sodium bicarbonate added to the residue, extracted with ethyl acetate twice, dried over MgSO4, filtered, and concentrated in vacuo. Methanol/CH2Cl2 (50/50) was added, then the precipitate was filtered and dried, giving (E)-4-(4-(1-(benzyloxyimino)ethyl)-phenyl)-1,2,4-triazolidine-3,5-dione (I-5a: 167 mg, 23%) as a white solid. LC-MS (M+1) 325.1, t=1.77 minutes. 1 H NMR (400 MHz, DMSO-d6) δ ppm 2.60 (s, 3 H) 7.68 (d, J=8.84 Hz, 2 H) 8.05 (d, J=8.59 Hz, 2 H) 10.65 (s, 2 H). 1H NMR (400 MHz, CD3CN) δ ppm 2.29 (s, 3 H) 5.26 (s, 2 H) 7.37 (d, J=7.07 Hz, 1 H) 7.42 (t, J=7.33 Hz, 2 H) 7.45-7.50 (m, 2 H) 7.53 (d, J=8.59 Hz, 2 H) 7.75-7.93 (m, 4 H).

1. filtrationfiltered
2. concentrationconcentrated in vacuo
3. additionSaturated sodium bicarbonate added to the residue
4. extractionextracted with ethyl acetate twice
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. additionMethanol/CH2Cl2 (50/50) was added
9. filtrationthe precipitate was filtered
10. customdried