反応 #47400

反応方程式

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

2,6-difluoro-3-methoxy-phenol

ethyl-2-butynoate

→

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

収率 76.1%

溶媒

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

反応条件

後処理

1. 1
   workup.ADDITIONAfter addition
2. 2
   温度at reflux overnight
3. 3
   その他was removed in vacuo
4. 4
   workup.ADDITIONthe residue was diluted in diethyl ether
5. 5
   洗浄washed first with 1N aqueous hydrochloric acid
6. 6
   乾燥10% aqueous sodium hydroxide solution, a saturated sodium chloride solution and dried over magnesium sulfate
7. 7
   ろ過The mixture was filtered
8. 8
   その他evaporated
9. 9
   その他the residue purified by ISCO column chromatography (Teledyne Isco RediSep Flash Column 120 g, 0% to 15%) ethyl acetate/hexanes which

実験手順

To a stirred mixture of 2,6-difluoro-3-methoxy-phenol (5.00 g, 0.031 mol) and ethyl-2-butynoate (7.00 g, 0.062 mol) in tetrahydrofuran (40 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (4.76 g, 0.031 mol) in tetrahydrofuran (10 mL) slowly. After addition was complete the mixture was stirred at reflux overnight. 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 and the residue purified by ISCO column chromatography (Teledyne Isco RediSep Flash Column 120 g, 0% to 15%) ethyl acetate/hexanes which afforded (E)-3-(2,6-difluoro-3-methoxy-phenoxy)-but-2-enoic acid ethyl ester (6.42 g, 76%) as a colorless oil.

出典