Reaktionsgleichung
[Br:1]Br.[CH3:3][O:4][C:5](=[O:15])[C:6]1[CH:11]=[C:10]([O:12][CH3:13])[CH:9]=[CH:8][C:7]=1[OH:14].COC(C)(C)C>CCCCCCC.O>[CH3:3][O:4][C:5](=[O:15])[C:6]1[CH:11]=[C:10]([O:12][CH3:13])[CH:9]=[C:8]([Br:1])[C:7]=1[OH:14]Komponenten
Versuchsvorschrift
In the course of from 30 to 45 minutes, at 20°, with stirring, 43.9 g of bromine are added dropwise to a solution of 45.9 g of 2-hydroxy-5-methoxy-benzoic acid methyl ester in 125 ml of heptane. The reaction mixture is then stirred for a further 3 to 4 hours, then diluted with 110 ml of water and stirred for a further one hour and then 295 ml of heptane and 46 ml of tert-butyl methyl ether are added thereto. The mixture is then heated to from 50° to 55° and the aqueous phase is separated off. The organic phase is extracted twice with 114 ml of water each time and cooled to -20°. The crystals which precipitate are filtered off and dried under a high vacuum. 3-Bromo-2-hydroxy-5-methoxy-benzoic acid methyl ester is thus obtained; yield 82.5% of the theoretical yield.
Aufarbeitung
- stirringThe reaction mixture is then stirred for a further 3 to 4 hours
- stirringstirred for a further one hour
- temperatureThe mixture is then heated to from 50° to 55°
- customthe aqueous phase is separated off
- extractionThe organic phase is extracted twice with 114 ml of water each time
- temperaturecooled to -20°
- filtrationThe crystals which precipitate are filtered off
- customdried under a high vacuum
Quellen und Nachweise
- ORD-Eintrag
- ord-a893f363e49043b88b78e74c554c5397
- Quelldatensatz
- uspto-grants-1994_03
- Patentnummer
- US05290939
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