반응 #65431

반응 방정식

potassium carbonate

ethyl 2,3-dibromopropionate

catechol

→

Ethyl 2,3-dihydro-1,4-benzodioxin-2-carboxylate

수율 80.0%

용매

acetone

반응 조건

후처리

1. 1
   기타at intervals of 15 minutes
2. 2
   온도The reaction mixture is heated
3. 3
   온도at reflux for 18 hours
4. 4
   온도cooled
5. 5
   여과filtered through Celite
6. 6
   농축The filtrate is concentrated to a residual volume of 60 cm3
7. 7
   추출hydrolysed with 80 cm3 of water and extracted with diethyl ether
8. 8
   건조After drying over magnesium sulfate
9. 9
   농축the ethereal phase is concentrated under reduced pressure
10. 10
    workup.DISTILLATIONthe crude product is purified by distillation under reduced pressure (b.p.=155° C. under 15 mm Hg)

실험 절차

Under a nitrogen atmosphere, add 18.2 g (131 mmol) of dry potassium carbonate and 13 g (50 mmol) of ethyl 2,3-dibromopropionate in succession to a solution of 20 g (18 1 mmol) of catechol dissolved in 120 cm3 of anhydrous acetone. The operation is repeated four times in succession at intervals of 15 minutes. The reaction mixture is heated at reflux for 18 hours, and then cooled and filtered through Celite. The filtrate is concentrated to a residual volume of 60 cm3, then hydrolysed with 80 cm3 of water and extracted with diethyl ether. After drying over magnesium sulfate, the ethereal phase is concentrated under reduced pressure and the crude product is purified by distillation under reduced pressure (b.p.=155° C. under 15 mm Hg). Ethyl 2,3-dihydro-1,4-benzodioxin-2-carboxylate is thereby obtained in a yield of 80%. nD25 =1.5214 ##STR25##

출처