反应详情

To a stirred mixture of 3-ethoxy-2-fluoro-phenol (6.00 g, 0.038 mol) and ethyl-2-butynoate (8.60 g, 0.077 mol) in tetrahydrofuran (50 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (5.80 g, 0.038 mol) slowly. After addition was complete the mixture was stirred at reflux for 7 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 crude product, (E)-3-(3-ethoxy-2-fluoro-phenoxy)-but-2-enoic acid ethyl ester, was obtained as a brown oil (6.00 g, 58%) and used without further purification.

1. additionAfter addition
2. temperatureat reflux for 7 h
3. customwas removed in vacuo
4. additionthe residue was diluted in diethyl ether
5. washwashed first with 1N aqueous hydrochloric acid
6. dry with material10% aqueous sodium hydroxide solution, a saturated sodium chloride solution and dried over magnesium sulfate