Reacción #1909781

Ecuación de reacción

hexane

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

tert-butyl hypochlorite

→

title compound

Rendimiento 37.0%

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

Rendimiento 37.0%

Disolventes

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturacooling
2. 2
   Temperaturathe mixture was cooled with ice
3. 3
   Otroprecipitation of crystals
4. 4
   FiltraciónThe 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
   Temperaturathe mixture was refluxed
8. 8
   Temperaturaunder heating for 18 hours
9. 9
   ConcentraciónThe reaction mixture was concentrated
10. 10
    workup.ADDITIONa 10% aqueous citric acid solution was added to the residue, which
11. 11
    Extracciónwas followed by extraction with ethyl acetate
12. 12
    LavadoThe organic layer was washed with water and saturated brine
13. 13
    Secadodried over anhydrous sodium sulfate
14. 14
    ConcentraciónThe organic layer was concentrated under reduced pressure

Procedimiento

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%).

Fuente