Hydrochloric Acid → HCID 23050504, compound

Participants

Reaction Steps

8.7 ml of n-butyllithium solution (1.6M in hexane) were added at -78° to a solution of 3.0 g (13.5 mmol) of 1-(3,4,5-trimethoxyphenyl)-2-propyn-1-ol in 40 ml of ether. The reaction mixture was brought to -30°, whereupon 1.8 ml (14.2 mmol) of freshly distilled trimethylsilyl chloride were added at -30°. Thereafter, the mixture was warmed to 0°. stirred and cooled to -78° for 1 hour, whereupon 7.8 ml of n-butyllithium solution (1.6M in hexane) were added. The reaction mixture was stirred at -30° for 1 hour and then treated at -30° with 2.77 ml (20.25 mmol) of butyl chloroformate, whereupon the mixture was stirred at -30° for 30 minutes and at 0° for 1 hour and 150 ml of 1N hydrochloric acid and 150 ml of ethyl acetate were added. Subsequently. 30 ml of 25% hydrochloric acid were added, the mixture was shaken vigorously for 10 minutes in a separating funnel, the aqueous phase was extracted twice with ethyl acetate, the combined organic phases were dried over magnesium sulphate and the solvent was distilled off. The crude product which remained behind as the residue was taken up in 10 ml of methylene chloride and added dropwise at 0° to a suspension 35.2 g (0.405 mol) of manganese dioxide in 50 ml of methylene chloride The reaction mixture was stirred at 0° for 1.5 hours, filtered over magnesium sulphate and evaporated. After chromatography of the residue on silica gel with ethyl acetate/hexane (1:4) there was obtained butyl 3-(3,4,5-trimethoxybenzoyl)propiolate as a pale yellowish oil.

Provenance & Evidence