Sulfuric Acid → 4-(4-Bromo-2-ethylphenyl)-2,6-diethyl-2,6-dimethylpyran-3,5-dione

HRID 341672ノート

反応式

HRID 341672 の反応式
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[C:10]3([C:14](=[O:15])[C:13]([CH2:17][CH3:18])([CH3:16])[O:12][C:11]3([CH2:20][CH3:21])[CH3:19])[O:9]2)=[C:4]([CH2:22][CH3:23])[CH:3]=1.S(=O)(=O)(O)O>ClCCl>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[C:14](=[O:15])[C:13]([CH2:17][CH3:18])([CH3:16])[O:12][C:11]([CH2:20][CH3:21])([CH3:19])[C:10]2=[O:9])=[C:4]([CH2:22][CH3:23])[CH:3]=1

参加物

4

反応物 2

HCID 1118Sulfuric AcidHCID 595627242-(4-Bromo-2-ethylphenyl)-4,6-diethyl-4,6-dimethyl-1,5-dioxaspiro[2.4]heptan-7-one

生成物 1

HCID 687339294-(4-Bromo-2-ethylphenyl)-2,6-diethyl-2,6-dimethylpyran-3,5-dione収率 13.2%

試薬・触媒・溶媒 1

HCID 6344Dichloromethane溶媒

反応条件

温度
7.5 °C

実験手順

To an ice cold solution of 2-(4-bromo-2-ethylphenyl)-4,6-diethyl-4,6-dimethyl-1,5-dioxaspiro[2.4]heptan-7-one (15 g, 0.0397 mol) in dichloromethane (7.5 ml) is added concentrated sulphuric acid (45 ml), dropwise over 50-60 minutes, maintaining the temperature of the reaction mixture at 5-10° C. The reaction mixture is maintained at 5-10° C. for 10-15 minutes, quenched into crushed ice (225 g) and extracted with dichloromethane (3×100 ml). The organic phases are combined, washed with water, and dried over anhydrous sodium sulfate. The mixture is filtered, and the filtrate is evaporated under reduced pressure. The residue is purified by column chromatography on silica gel to give 4-(4-bromo-2-ethylphenyl)-2,6-diethyl-2,6-dimethylpyran-3,5-dione (2 g) as a white solid.

後処理

  1. temperatureThe reaction mixture is maintained at 5-10° C. for 10-15 minutes
  2. customquenched
  3. custominto crushed ice (225 g)
  4. extractionextracted with dichloromethane (3×100 ml)
  5. washwashed with water
  6. dry with materialdried over anhydrous sodium sulfate
  7. filtrationThe mixture is filtered
  8. customthe filtrate is evaporated under reduced pressure
  9. customThe residue is purified by column chromatography on silica gel

出典と根拠

ORDレコード
ord-df99c1ae7da04a8588d08dd1553b2b60
出典データセット
uspto-grants-2014_11
特許番号
US08895761B2

反応ノート

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