Acetic Anhydride → 1-Acetyl-4-phenyl-1,2,4-triazolidine-3,5-dione
反応式
[C:1]1([N:7]2[C:11](=[O:12])[NH:10][NH:9][C:8]2=[O:13])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[C:14](OC(=O)C)(=[O:16])[CH3:15]>C(Cl)(Cl)Cl>[CH3:15][C:14]([N:10]1[C:11](=[O:12])[N:7]([C:1]2[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=2)[C:8](=[O:13])[NH:9]1)=[O:16]参加物
4
実験手順
To a suspension of 5.3 g (30 mmol) of 4-phenyl-1,2,4-triazolidine-3,5-dione in 175 ml of chloroform was added dropwise over a 15 minute period 45.9 g (450 mmol) of acetic anhydride with stirring. The reaction mixture was stirred at room temperature for five days. The reaction mixture was filtered to remove a white precipitate which was washed with 30 ml of chloroform to give 3.55 g (54.0 %) of 1-methylcarbonyl-4-phenyl-1,2,4-triazolidine-3,5-dione as white solid, m.p. 215°-218.5° C. The filtrate Was washed with three 100 ml portions of water and three 80 ml portions of 10% sodium carbonate. The carbonate washings were acidified with concentrated hydrochloric acid. No precipitate was formed. The chloroform solution was dried (Na2SO4) and evaporated under reduced pressure to give a liquid residue containing acetic anhydride. The filtered solid was recrystallized from 95% ethanol to yield pure 1-methylcarbonyl-4-phenyl-1,2,4-triazolidine-3,5-dione: m.p. 216.5° -218.5° C.; IR (Nujol) 1726, 1710, 1688 cm-1 (CO); 1H NMR (60 MHz, CDCl3) δ 7.90 (s, 5H) 2.55(s, 3H). Found: C, 54.5; H, 4.2: N, 19.4. C10H9N3O3 requires C, 54.8; H, 4.2; N, 19.4.