반응 #1150

반응 방정식

methyl 2-formyl-5-methoxyphenoxyacetate

1,8-diazabicyclo[5.4.0]-7-undecene

→

methyl 6-methoxybenzofuran-2-carboxylate

수율 57.0%

용매

toluene

반응 조건

후처리

1. 1
   온도was heated under refluxing conditions for 4 hours
2. 2
   농축The reaction mixture was concentrated under reduced pressure
3. 3
   workup.ADDITIONafter 6N hydrochloric acid was added
4. 4
   추출the residue was extracted with ethyl acetate
5. 5
   세척After the ethyl acetate layer was washed with water
6. 6
   건조dried (MgSO4)
7. 7
   workup.DISTILLATIONthe solvent was distilled off
8. 8
   workup.ADDITION10% hydrochloric acid-methanol (30 ml) was added to the residue
9. 9
   온도by heating at 70° to 80° C. for 4 hours
10. 10
    농축The reaction mixture was concentrated under reduced pressure
11. 11
    workup.ADDITIONwater was added
12. 12
    추출followed by extraction with ethyl acetate
13. 13
    세척After the ethyl acetate layer was washed with water
14. 14
    건조dried (MgSO4)
15. 15
    workup.DISTILLATIONthe solvent was distilled off
16. 16
    세척From the fraction eluted with chloroform-hexane (1:2

실험 절차

A mixture of methyl 2-formyl-5-methoxyphenoxyacetate (27.7 g), 1,8-diazabicyclo[5.4.0]-7-undecene (40.8 g) and toluene (200 ml) was heated under refluxing conditions for 4 hours. The reaction mixture was concentrated under reduced pressure; after 6N hydrochloric acid was added, the residue was extracted with ethyl acetate. After the ethyl acetate layer was washed with water and dried (MgSO4), the solvent was distilled off; 10% hydrochloric acid-methanol (30 ml) was added to the residue, followed by heating at 70° to 80° C. for 4 hours. The reaction mixture was concentrated under reduced pressure; water was added, followed by extraction with ethyl acetate. After the ethyl acetate layer was washed with water and dried (MgSO4), the solvent was distilled off; the residue was subjected to silica gel column chromatography. From the fraction eluted with chloroform-hexane (1:2, v/v), methyl 6-methoxybenzofuran-2-carboxylate (14.3 g, 57%) was obtained, which was then recrystallized from dichloromethane-isopropyl ether to yield colorless prisms having a melting point of 97° to 98° C.

출처