反应详情

Sodium hydride (1.44 grams of a 60% suspension in mineral oil), 1.46 ml of ethyl formate and 3 drops of ethanol were combined in 150 ml of anhydrous tetrahydrofuran and stirred at room temperature for 30 minutes. A solution of 4 grams of 1-benzyl-5,6-dihydro-4(1H)-cyclopentapyrazolone in 50 ml of anhydrous tetrahydrofuran was added dropwise and the reaction mixture was heated at reflux for 16 hours. An additional 1.44 grams of sodium hydride suspension and 1.46 ml of ethyl formate were then added and the reaction mixture was heated at reflux for 2 hours. The mixture was cooled, diluted with 150 ml of water, and washed with ethyl ether. The aqueous layer was acidified with aqueous hydrochloric acid and the solid which formed was collected by filtration to give 1-benzyl-5,6-dihydro-5-hydroxymethylene-4(1H)-cyclopentapyrazolone as a tan solid melting at about 171°-172° C.

1. temperaturethe reaction mixture was heated
2. temperatureat reflux for 16 hours
3. temperaturethe reaction mixture was heated
4. temperatureat reflux for 2 hours
5. temperatureThe mixture was cooled
6. washwashed with ethyl ether
7. customthe solid which formed
8. filtrationwas collected by filtration