反应详情

Sodium (0.6 g, 0.026 g atom) was dissolved in absolute ethanol (200 mL) and diethyl 2,4-dioxoimidazolidine-5-phosphonate (6.0 g, 25 mmol) added. After 10 minutes, 2-nitro-5-(1-piperidinyl)benzaldehyde (5.0 g, 21 mmol) was added in one portion and the mixture stirred at room temperature for 5 hours. The yellow precipitate was filtered off, washed with water and dried in air to give 5-[[2-nitro-5-(1-piperidinyl)phenyl]methylene]-2,4-imidazolidinedione (6.17 g, 92%), m.p. 273°-276° C. A sample dried in vacuo in 110° C. had m.p. 280° C. (dec.).

1. filtrationThe yellow precipitate was filtered off
2. washwashed with water
3. customdried in air