反应详情

Ethyl chlorooxoacetate (0.57 mL, 5.03 mmol) was added to a stirring solution of the above thiourea (1.00 g, 3.87 mmol) in dichloromethane (15 mL) and the resulting mixture was stirred overnight at room temperature. Concentration, trituration of the residue with diethyl ether, and recrystallization from boiling methanol afforded 0.66 g (55%) of 1-(2,4-difluoro-phenyl)-3-(2,2-dimethyl-propyl)-2-thioxo-imidazolidine-4,5-dione as a yellow solid: mp 156.2–156.9° C.; 1H NMR (DMSO-d6): δ 7.55 (m, 2H), 7.30 (m, 1H), 3.76 (m, 2H), 0.95 (s, 9H); IR (KBr): 3510 2920, 2230, 1775 cm1; MS (m/z) 312 (M+).

1. concentrationConcentration, trituration of the residue
2. customwith diethyl ether, and recrystallization