Toluene → Methyl 5-bromo-2-methylbenzoate

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.

1. dry with materialTo 50 g of Na-X type zeolite dry
2. custompowder (Zeolum type F-9; 100 meshes or finer, produced by Tosoh Corporation)
3. stirringat 45˜50° C., and the mixture was stirred at 80° C. for 1 hour
4. stirringThe mixture was stirred at room temperature for 10 minutes
5. filtrationfiltered
6. washThe residual zeolite powder was washed
7. temperaturewith warmed hydrous methanol (10%, 250 ml)
8. concentrationconcentrated
9. additionThe residue was diluted with ethyl acetate
10. washwashed twice with water
11. customdried
12. concentrationconcentrated
13. washeluted with n-hexane

ORD record

ord-a161a4589deb487292b225297413390a

Source dataset

uspto-grants-2002_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06489487B1