تفاعل #1909781

معادلة التفاعل

hexane

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

tert-butyl hypochlorite

→

title compound

المردود 37.0%

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

المردود 37.0%

المذيبات

ethyl acetate

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةcooling
2. 2
   درجة الحرارةthe mixture was cooled with ice
3. 3
   أخرىprecipitation of crystals
4. 4
   ترشيحThe 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
   درجة الحرارةthe mixture was refluxed
8. 8
   درجة الحرارةunder heating for 18 hours
9. 9
   تركيزThe reaction mixture was concentrated
10. 10
    workup.ADDITIONa 10% aqueous citric acid solution was added to the residue, which
11. 11
    استخلاصwas followed by extraction with ethyl acetate
12. 12
    غسيلThe organic layer was washed with water and saturated brine
13. 13
    تجفيفdried over anhydrous sodium sulfate
14. 14
    تركيزThe organic layer was concentrated under reduced pressure

الإجراء التجريبي

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%).

المصدر