Sodium borohydride → Methyl 2-(3,4-dichlorophenyl)-4-hydroxy-2-methylchroman-3-carboxylate

HRID 409514Notes

Reaction equation

HRID 409514 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([C:9]2([CH3:24])[CH:18]([C:19]([O:21][CH3:22])=[O:20])[C:17](=[O:23])[C:16]3[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=3)[O:10]2)[CH:5]=[CH:6][C:7]=1[Cl:8].[BH4-].[Na+]>C1COCC1.CO>[Cl:1][C:2]1[CH:3]=[C:4]([C:9]2([CH3:24])[CH:18]([C:19]([O:21][CH3:22])=[O:20])[CH:17]([OH:23])[C:16]3[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=3)[O:10]2)[CH:5]=[CH:6][C:7]=1[Cl:8]

Participants

5

Reactant 2

HCID 4311764Sodium borohydride2×HCID 67155925Methyl 2-(3,4-dichlorophenyl)-2-methyl-4-oxochroman-3-carboxylate

Product 1

HCID 67155870Methyl 2-(3,4-dichlorophenyl)-4-hydroxy-2-methylchroman-3-carboxylateYield 98.6%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of methyl 2-(3,4-dichlorophenyl)-2-methyl-4-oxochroman-3-carboxylate (490 mg, 1.34 mmol) in THF (2.0 mL) was diluted with methanol (4.0 mL) and treated at rt with sodium borohydride (51 mg, 1.34 mmol). Additional sodium borohydride was added after 4 h. After 2.5 h more the solution was concentrated under vacuum. The residue was partitioned between water (containing a few drops of 1.0 M aqueous sodium hydroxide) and ethyl acetate. The organic phase was dried over sodium sulfate and concentrated under vacuum to provide crude methyl 2-(3,4-dichlorophenyl)-4-hydroxy-2-methylchroman-3-carboxylate as a white solid (485 mg, 98%), which was used without further purification. Mass spectrum m/z 389, 391 (M+Na)+.

Workup

  1. concentrationAfter 2.5 h more the solution was concentrated under vacuum
  2. customThe residue was partitioned between water (containing a few drops of 1.0 M aqueous sodium hydroxide) and ethyl acetate
  3. dry with materialThe organic phase was dried over sodium sulfate
  4. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-3d8c31778ece4cc2b52d785d8d108e88
Source dataset
uspto-grants-2014_06
Patent number
US08759390B2

Reaction notes

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