反応 #1909781

反応方程式

hexane

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

tert-butyl hypochlorite

→

title compound

収率 37.0%

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

収率 37.0%

溶媒

ethyl acetate

反応条件

後処理

1. 1
   温度cooling
2. 2
   温度the mixture was cooled with ice
3. 3
   その他precipitation of crystals
4. 4
   ろ過The 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
   温度the mixture was refluxed
8. 8
   温度under heating for 18 hours
9. 9
   濃縮The reaction mixture was concentrated
10. 10
    workup.ADDITIONa 10% aqueous citric acid solution was added to the residue, which
11. 11
    抽出was followed by extraction with ethyl acetate
12. 12
    洗浄The organic layer was washed with water and saturated brine
13. 13
    乾燥dried over anhydrous sodium sulfate
14. 14
    濃縮The organic layer was concentrated under reduced pressure

実験手順

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%).

出典