反应详情

A 8.5 g quantity of 5'-chloro-2'-hydroxyacetophenone and 6.0 g of p-tolualdehyde were dissolved in 105 ml of ethanol. Then 17 ml of an aqueous solution containing 10 g of sodium hydroxide was slowly added thereto dropwise and stirred at room temperature for 4 hours. Then 350 ml of ethanol and 17 ml of an aqueous solution containing 3.5 g of sodium hydroxide were added to the reaction mixture, and 8.3 ml of a 30% aqueous hydrogen peroxide solution was further added dropwise slowly and stirred at room temperature for 12 hours. A 10% aqueous HCl solution was added to adjust the reaction mixture to pH 3. The crystals precipitated were collected by filtration and washed serially with 10 ml of water, 5 ml of ethanol and 10 ml of diethyl ether, thus giving 6.0 g of 6-chloro-3-hydroxy-2-(4-methylphenyl)-4H-1-benzopyran-4-one as crystals.

1. additionwas slowly added
2. additionwas further added dropwise slowly
3. stirringstirred at room temperature for 12 hours
4. customThe crystals precipitated
5. filtrationwere collected by filtration
6. washwashed serially with 10 ml of water, 5 ml of ethanol and 10 ml of diethyl ether