Hydrochloric Acid → 4-[4-[(E)-C-methyl-N-phenylmethoxycarbonimidoyl]phenyl]-1,2,4-triazolidine-3,5-dione

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Reaction Conditions

Reaction Steps

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).

Provenance & Evidence