反应详情

In 1.2 l of ethanol was suspended 132 g of ethyl {[5-chloro-3-(2-methylphenyl)-4-oxo-4H-1-benzopyran-7-yl]oxy}acetate, and 0.53 l of a 1N sodium hydroxide aqueous solution was slowly added dropwise to the suspension at room temperature, followed by stirring at room temperature for 3 hours. The insoluble material was removed by filtration, and the filtrate was acidified with hydrochloric acid while ice-cooling and stirring. The stirring was continued at room temperature overnight. The precipitated crystals were collected by filtration, washed with water, and dried to obtain 105 g of the entitled compound having a melting point of 191° to 192° C.

1. additionwas slowly added dropwise to the suspension at room temperature
2. customThe insoluble material was removed by filtration
3. temperaturecooling
4. stirringstirring
5. waitThe stirring was continued at room temperature overnight
6. filtrationThe precipitated crystals were collected by filtration
7. washwashed with water
8. customdried