Dimethyl Sulfate → Methyl 4-bromo-3,5-dimethoxybenzoate
Reaktionsgleichung
[Br:1][C:2]1[C:10](O)=[CH:9]C(C(O)=O)=[CH:4][C:3]=1[OH:12].[C:13](=O)([O-])[O-].[K+].[K+].S([O:24][CH3:25])(OC)(=O)=O.[C:26]([O:29][CH2:30]C)(=[O:28])[CH3:27]>>[Br:1][C:2]1[C:3]([O:12][CH3:13])=[CH:4][C:27]([C:26]([O:29][CH3:30])=[O:28])=[CH:9][C:10]=1[O:24][CH3:25]Komponenten
5
Reaktionsbedingungen
- Temperatur
- 65 °C
Versuchsvorschrift
To a suspension of 4-bromo-3,5-dihydroxybenzoic acid (95.0 kg) in ethyl acetate (950 L) were added anhydrous potassium carbonate (270.8 kg) and dimethyl sulfate (174.7 kg). The mixture was heated at 50-80° C. for about 4 hours and partitioned by adding water. The organic layer was washed with water and saturated aqueous NaCl solution and concentrated under reduced pressure. The residue was suspended into methanol, stirred under heating and cooled. The crystalline precipitates were collected by filtration and dried to yield methyl 4-bromo-3,5-dimethoxybenzoate (98.8 kg) as pale yellow crystals.
Aufarbeitung
- custompartitioned
- additionby adding water
- washThe organic layer was washed with water and saturated aqueous NaCl solution
- concentrationconcentrated under reduced pressure
- temperatureunder heating
- temperaturecooled
- customThe crystalline precipitates
- filtrationwere collected by filtration
- customdried
Quellen und Nachweise
- ORD-Eintrag
- ord-6f717bfc8cc1491dbf06b23c14eaf4a6
- Quelldatensatz
- uspto-grants-2009_01
- Patentnummer
- US07476758B2
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