Ammonium Chloride → Ethyl 5-(2,4-dimethoxyphenyl)-2,4-pentadienoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To 9.00 g (72.2 mmol) of 50% potassium butoxide, 200 ml of anhydrous tetrahydrofuran was added in the atmosphere of argon. To the mixture, cooled to 0° C., was added dropwise a solution of 25.81 g (72.2 mmol) of triethyl-4-phosphocrotonate dissolved in 30 ml of anhydrous tetrahydrofuran through a dropping funnel over 30 minutes. After 30 min., a solution of 10 g (60.2 mmol) of 2,4-dimethoxybenzaldehyde dissolved in 30 ml of anhydrous tetrahydrofuran was added dropwise through a dropping funnel over 10 minutes. Temperature of the reaction mixture was raised from 0° C. to room temperature followed by stirring for 18 hours. To the resulting mixture were successively added saturated aqueous solution of ammonium chloride and water followed by extraction with ethyl acetate. The organic layer was washed with water and saturated aqueous solution of ammonium chloride, then dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a residue. It was subjected to column chromatography on silica, and from the ethyl acetate-hexane (1:7) eluate fraction was produced 9.44 g (36.0 mmol) of ethyl 5-(2,4-dimethoxyphenyl)-2,4-pentadienoate.

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