Toluene → Methyl 5-bromo-2-methylbenzoate

Participants

Reaction Steps

To 50 g of Na-X type zeolite dry powder (Zeolum type F-9; 100 meshes or finer, produced by Tosoh Corporation) was added dropwise 7.51 g (50.0 mmol) of methyl 2-methylbenzoate with stirring. Further, 3.9 ml (75 mmol) of bromine was added dropwise thereto at 45˜50° C., and the mixture was stirred at 80° C. for 1 hour. To the reaction mixture was added a solution of potassium carbonate (5.5 g) in water (50 ml) and methanol (250 ml). The mixture was stirred at room temperature for 10 minutes and filtered. The residual zeolite powder was washed with warmed hydrous methanol (10%, 250 ml). The filtrate and the washing were combined and concentrated. The residue was diluted with ethyl acetate, washed twice with water, dried and concentrated. The residue (2.98 g) was subjected to silica gel column chromatography (eluted with n-hexane:toluene=10:1 and then 5:1 and then 3:1) to obtain 1.97 g (8.60 mmol) of methyl 5-bromo-2-methylbenzoate as crystals.

Provenance & Evidence