Acetic Acid → 850785-06-7

Participants

Reaction Steps

25 g methyl-4-hydroxyphenylacetate, 14.5 ml 3-methylbut-2-enal and 18.3 g phenylboronic acid were placed together under nitrogen atmosphere in 1 l dry toluene and heated to boiling for 7 hours under reflux cooling. Then 60 ml glacial acetic acid was added to this receiving solution at room temperature (=RT) and the mixture was again heated to boiling for 7 hours under reflux cooling. It was allowed to cool to room temperature, the solvent was largely evaporated at reduced pressure and the remaining residue was poured into 300 ml of a 1:1 (v/v) mixture of ethyl acetate (═EA) and water. The pH value was adjusted to 5 by addition of solid sodium bicarbonate, the organic phase was separated off and largely evaporated at reduced pressure. Chromatography of the remaining residue on silica gel (mobile phase: petroleum ether/EA 10:1 v/v) yielded 16 g methyl-(2,2-dimethyl-2H-chromen-6-yl)acetate as pale yellow oil.

Provenance & Evidence