2,3-Dichlorophenol → 3-(2,3-Dichoro-phenoxy)-but-2-enoic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Potassium t-butoxide (11.2 g, 0.100 mol) was added to a stirred solution of 2,3-dichlorophenol (8.2 g, 0.05 mol) in tetrahydrofuran (40 mL) at 23° C. under nitrogen and the reaction mixture was heated to reflux for 0.75 h. The reaction mixture was cooled to 23° C. and a solution of 3-chloro-but-2-enoic acid ethyl ester (6.5 g, 0.044 mol) in tetrahydrofuran (40 mL) was added to the reaction mixture. The reaction mixture was refluxed for an additional 3 h. After this time, the mixture was concentrated in vacuo and the residue was diluted with water and extracted with diethyl ether. The organic layer was then washed with 5% sodium hydroxide solution followed by a saturated sodium chloride solution. The combined organic layers were separated, dried over sodium sulfate and concentrated in vacuo to afford 3-(2,3-dichoro-phenoxy)-but-2-enoic acid ethyl ester (9.20 g, 76%) as a yellow oil.

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