تفاعل #1150

معادلة التفاعل

methyl 2-formyl-5-methoxyphenoxyacetate

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

→

methyl 6-methoxybenzofuran-2-carboxylate

المردود 57.0%

المذيبات

toluene

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةwas heated under refluxing conditions for 4 hours
2. 2
   تركيزThe reaction mixture was concentrated under reduced pressure
3. 3
   workup.ADDITIONafter 6N hydrochloric acid was added
4. 4
   استخلاصthe residue was extracted with ethyl acetate
5. 5
   غسيلAfter the ethyl acetate layer was washed with water
6. 6
   تجفيفdried (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
   درجة الحرارةby heating at 70° to 80° C. for 4 hours
10. 10
    تركيزThe reaction mixture was concentrated under reduced pressure
11. 11
    workup.ADDITIONwater was added
12. 12
    استخلاصfollowed by extraction with ethyl acetate
13. 13
    غسيلAfter the ethyl acetate layer was washed with water
14. 14
    تجفيفdried (MgSO4)
15. 15
    workup.DISTILLATIONthe solvent was distilled off
16. 16
    غسيلFrom the fraction eluted with chloroform-hexane (1:2

الإجراء التجريبي

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.

المصدر