Dimethyl Sulfate → Methyl 3-bromo-2-methoxy-6-methylbenzoate

Participants

Reaction Steps

A mixture of methyl 3-bromo-2-hydroxy-6-methylbenzoate (Intermediate 44, 114.5 g), dimethyl sulfate (61 mL) and potassium carbonate (166 g) in acetone (11) was heated at reflux for 2.5 hours. After cooling, the mixture was filtered and the filtrate was evaporated to dryness. The residue was dissolved in DCM and washed with water, dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica, eluting with a mixture of tert-butyl methyl ether and pentane with a gradient of 0-40%. The product was purified again by chromatography on silica, eluting with a mixture of tert-butyl methyl ether and pentane with a gradient of 0-10%. The product was again purified by chromatography on silica, eluting with a mixture of tert-butyl methyl ether and pentane with a gradient of 0-10% to give methyl 3-bromo-2-methoxy-6-methylbenzoate (66 g).

Provenance & Evidence