Sodium cyanoborohydride → 4-Hydroxy-5-hydroxymethyl-3-methyl-benzofuran-2-carboxylic acid tert-butyl ester

HRID 29428Notes

Reaction equation

HRID 29428 reaction equation
[C:1]([O:5][C:6]([C:8]1[O:9][C:10]2[CH:17]=[CH:16][C:15]([CH:18]=[O:19])=[C:14]([OH:20])[C:11]=2[C:12]=1[CH3:13])=[O:7])([CH3:4])([CH3:3])[CH3:2].C([BH3-])#N.[Na+]>C1COCC1>[C:1]([O:5][C:6]([C:8]1[O:9][C:10]2[CH:17]=[CH:16][C:15]([CH2:18][OH:19])=[C:14]([OH:20])[C:11]=2[C:12]=1[CH3:13])=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

4

Reactant 2

HCID 5003444Sodium cyanoborohydrideHCID 865990315-Formyl-4-hydroxy-3-methyl-benzofuran-2-carboxylic acid tert-butyl ester

Product 1

HCID 687148834-Hydroxy-5-hydroxymethyl-3-methyl-benzofuran-2-carboxylic acid tert-butyl esterYield 46.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To 5-formyl-4-hydroxy-3-methyl-benzofuran-2-carboxylic acid tert-butyl ester (430 mg, 1.56 mmol) was added 8 mL of THF, followed by sodium cyanoborohydride (117 mg, 1.87 mmol) in one portion. The solution was stirred at room temperature for 1 h and then placed in a 65° C. oil bath overnight. The solvent was removed under vacuum and water was added. The mixture was extracted with ethyl acetate. Removal of the solvent gave the crude product, which was purified by column chromatography to give 200 mg of 4-hydroxy-5-hydroxymethyl-3-methyl-benzofuran-2-carboxylic acid tert-butyl ester was obtained as a yellow semi-solid.

Workup

  1. customplaced in a 65° C.
  2. customovernight
  3. customThe solvent was removed under vacuum and water
  4. additionwas added
  5. extractionThe mixture was extracted with ethyl acetate
  6. customRemoval of the solvent
  7. customgave the crude product, which
  8. customwas purified by column chromatography

Sources & evidence

ORD record
ord-72639567ca744487a982e8df8a237384
Source dataset
uspto-grants-2008_09
Patent number
US07420001B2

Reaction notes

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