Methylparaben → Methyl 4-(allyloxy)benzoate

Participants

Reaction Steps

To a nitrogen flushed 5 L three neck round bottom flask fitted with a mechanical stirrer, condenser, and a nitrogen inlet was charged 608 g (4 mol) of methyl 4-hydroxybenzoate, 520 ml (727 g, 6.00 mol, 1.5 eq) of allyl bromide, 663 g (9.6 mol of anhydrous potassium carbonate, and 2.3 L of acetone. The mixture was refluxed with vigorous stirring for 90 min. Additional potassium carbonate, (50 g) was added, and 25 g added again after an additional 50 min. After 20 min (total reaction time of 160 min), the suspension was allowed to cool to ambient temperature and stirred overnight. The mixture was filtered and the cake washed with 3 L of acetone. The solution was concentrated to obtain 788.6 g (theoretical yield 768.9 g) of a pale yellow, almost colorless oil which was used without purification in the next step. The product was a single spot on TLC (silica-1:1 EtOAc/Hex) and the MNR was consistent with methyl 4-allyloxybenzoate.

Provenance & Evidence