反应详情

5-Hydroxy-2-methyl-4-pyrone, 6 g, was suspended in 25 ml of water and a pH of the suspension was adjusted to 10.5 with 50% sodium hydroxide. After 5 ml of 35% formalin was added to the suspension, the mixture was stirred at room temperature for 3 hours. After completion of the reaction, the reaction mixture was cooled to 5° C. and its pH was adjusted to 2.0 with 50% sulfuric acid. Then, the reaction solution was concentrated to about half and the resulting crystals were taken out by filtration and washed with a small quantity of chilled water to give 5.9 g of the title compound.

1. customAfter completion of the reaction
2. temperaturethe reaction mixture was cooled to 5° C.
3. concentrationThen, the reaction solution was concentrated to about half
4. filtrationthe resulting crystals were taken out by filtration
5. washwashed with a small quantity of chilled water