反应详情

To a warm (40° C.) solution of 41.5 grams (0.23 mole) of 3,4-dimethoxyacetophenone and 40.5 grams (0.27 mole) of piperonal in 220 milliliters of ethanol was added 60 milliliters of 10 % aqueous sodium hydroxide. The mixture was warmed for 10 minutes at 40°-50° C; then stirred at room temperature for 2 hours. After standing overnight, the yellow crystalline produce was collected by filtration, washed with water (3 × 40 milliliters), and dried to give 72 grams (quantitative yield) of V, melting point 127°-129° c. An analytical sample was prepared by recrystallization of 1.6 gram of the product from 50 milliliters of ethanol, giving 1.4 gram of pure chalcone as yellow needles, melting point 131°-133° C.; λ (ethanol) 242 (log ε 4.23), 3.60 nm (4.53).

1. temperatureThe mixture was warmed for 10 minutes at 40°-50° C
2. waitAfter standing overnight
3. customthe yellow crystalline produce
4. filtrationwas collected by filtration
5. washwashed with water (3 × 40 milliliters)
6. customdried