Reaktion #47424

Reaktionsgleichung

2,6-difluoro-3-isopropoxy-phenol

ethyl-2-butynoate

1,8-diazabicyclo[5.4.0]undec-7-ene

→

(E)-3-(2,6-difluoro-3-isopropoxy-phenoxy)-but-2-enoic acid ethyl ester

Ausbeute 75.0%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition
2. 2
   Temperaturat reflux for 6 h
3. 3
   Sonstigewas removed in vacuo
4. 4
   workup.ADDITIONthe residue was diluted in diethyl ether
5. 5
   Waschenwashed first with 1N aqueous hydrochloric acid
6. 6
   Trocknen10% aqueous sodium hydroxide solution, a saturated sodium chloride solution and dried over magnesium sulfate
7. 7
   FiltrationThe mixture was filtered
8. 8
   Sonstigeevaporated which

Vorschrift

To a stirred mixture of 2,6-difluoro-3-isopropoxy-phenol (5.74 g, 0.031 mol) and ethyl-2-butynoate (6.85 g, 0.061 mol) in tetrahydrofuran (50 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (4.64 g, 0.030 mol) slowly. After addition was complete the mixture was stirred at reflux for 6 h. Upon completion of the reaction the tetrahydrofuran was removed in vacuo and the residue was diluted in diethyl ether and washed first with 1N aqueous hydrochloric acid, then 10% aqueous sodium hydroxide solution, a saturated sodium chloride solution and dried over magnesium sulfate. The mixture was filtered and evaporated which afforded (E)-3-(2,6-difluoro-3-isopropoxy-phenoxy)-but-2-enoic acid ethyl ester as a brown oil (6.85 g, 75%) and used without further purification.

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