Reaktion #1909781

Reaktionsgleichung

hexane

2,4-dihydroxy-3-methylbenzoic acid methyl ester

tert-butyl hypochlorite

→

title compound

Ausbeute 37.0%

5-Chloro-2,4-dihydroxy-3-methylbenzoic acid

Ausbeute 37.0%

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooling
2. 2
   Temperaturthe mixture was cooled with ice
3. 3
   Sonstigeprecipitation of crystals
4. 4
   FiltrationThe crystals were collected by filtration
5. 5
   workup.DISSOLUTIONdissolved in a mixed solvent of methanol (20 ml) and tetrahydrofuran (THF, 20 ml)
6. 6
   workup.ADDITIONA 1M lithium hydroxide solution (40 ml) was added to the solution
7. 7
   Temperaturthe mixture was refluxed
8. 8
   Temperaturunder heating for 18 hours
9. 9
   EinengenThe reaction mixture was concentrated
10. 10
    workup.ADDITIONa 10% aqueous citric acid solution was added to the residue, which
11. 11
    Extraktionwas followed by extraction with ethyl acetate
12. 12
    WaschenThe organic layer was washed with water and saturated brine
13. 13
    Trocknendried over anhydrous sodium sulfate
14. 14
    EinengenThe organic layer was concentrated under reduced pressure

Vorschrift

To a solution of 2,4-dihydroxy-3-methylbenzoic acid methyl ester (9.9 g) in ethyl acetate (100 ml) was added tert-butyl hypochlorite (12.3 ml) under ice-cooling. After stirring for 2 hours, hexane (200 ml) was added, and the mixture was cooled with ice to allow precipitation of crystals. The crystals were collected by filtration, and dissolved in a mixed solvent of methanol (20 ml) and tetrahydrofuran (THF, 20 ml). A 1M lithium hydroxide solution (40 ml) was added to the solution, and the mixture was refluxed under heating for 18 hours. The reaction mixture was concentrated, and a 10% aqueous citric acid solution was added to the residue, which was followed by extraction with ethyl acetate. The organic layer was washed with water and saturated brine, and dried over anhydrous sodium sulfate. The organic layer was concentrated under reduced pressure to give the title compound (4.14 g, yield 37%).

Quelle