Ethanol → 4-(7-Bromo-1,3-benzodioxol-4-yl)-4-methyl-2-oxo-valeric acid-ethyl ester

HRID 2215481Notes

Reaction equation

HRID 2215481 reaction equation
[Br:1][C:2]1[C:7]2[O:8][CH2:9][O:10][C:6]=2[C:5]([C:11]([CH3:19])([CH3:18])[CH2:12][C:13](=[O:17])[C:14]([OH:16])=[O:15])=[CH:4][CH:3]=1.S(=O)(=O)(O)O.[CH2:25](O)[CH3:26]>>[CH2:25]([O:15][C:14](=[O:16])[C:13](=[O:17])[CH2:12][C:11]([C:5]1[C:6]2[O:10][CH2:9][O:8][C:7]=2[C:2]([Br:1])=[CH:3][CH:4]=1)([CH3:19])[CH3:18])[CH3:26]

Participants

4

Reactant 3

HCID 702EthanolHCID 1118Sulfuric AcidHCID 219488274-(7-Bromo-1,3-benzodioxol-4-yl)-4-methyl-2-oxo-valeric acid

Product 1

HCID 692037914-(7-Bromo-1,3-benzodioxol-4-yl)-4-methyl-2-oxo-valeric acid-ethyl ester

Procedure

300 mg of 4-(7-bromo-1,3-benzodioxol-4-yl)-4-methyl-2-oxo-valeric acid and 0.1 ml of sulfuric acid (96%) in 5 ml of ethanol are heated for 4 hours to 70° C. Then, the batch is concentrated by evaporation in a vacuum and added to water. It is extracted with ethyl acetate, washed with brine, dried and concentrated by evaporation in a vacuum. 272 mg of 4-(7-bromo-1,3-benzodioxol-4-yl)-4-methyl-2-oxo-valeric acid-ethyl ester is obtained as a yellow oil. This ester and 0.32 ml of trifluoromethyl-trimethylsilane in 4 ml of THF are mixed with 0.14 ml of a tetrabutylammonium fluoride solution (1 M in THF) at −70° C. It is stirred for 1 hour at −70° C., for 1.5 hours at −10° C., for 1 hour at 0° C. and for 2 hours at room temperature. Another spatula-tip full of tetrabutylammonium fluoride is added, and after stirring is continued for 20 minutes, it is added to water. It is extracted with ethyl acetate, washed with water, dried with sodium sulfate and concentrated by evaporation in a vacuum. 297 mg of 4-(7-bromo-1,3-benzodioxol-4-yl)-2-hydroxy-4-methyl-2-trifluoromethyl-valeric acid-ethyl ester is obtained as a yellow oil. This oil is mixed in 5 ml of ether at 0° C. with 29 mg of lithium aluminum hydride, and stirred for 1 hour at 0° C. and for another 10 hours at room temperature. The batch is added to dilute hydrochloric acid, extracted with ethyl acetate, washed with water, dried with sodium sulfate and concentrated by evaporation in a vacuum. 164 mg of 4-(7-bromo-1,3-benzodioxol-4-yl)-2-hydroxy-4-methyl-2-(trifluoromethyl)pentan-1-ol is obtained as a yellow oil.

Workup

  1. concentrationThen, the batch is concentrated by evaporation in a vacuum
  2. additionadded to water
  3. extractionIt is extracted with ethyl acetate
  4. washwashed with brine
  5. customdried
  6. concentrationconcentrated by evaporation in a vacuum

Sources & evidence

ORD record
ord-e6bee99f3aca4fa688a2858aa12f36b7
Source dataset
uspto-grants-2006_09
Patent number
US07109212B2

Reaction notes

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