Sodium borohydride → HCID 18763752, compound

HRID 431298Notes

Reaction equation

HRID 431298 reaction equation
[N+:1]([C:4]1[CH:12]=[CH:11][CH:10]=[C:9]([C:13](=[O:15])[CH3:14])[C:5]=1[C:6]([OH:8])=O)([O-:3])=[O:2].[BH4-].[Na+]>[OH-].[Na+]>[CH3:14][CH:13]1[C:9]2[C:5](=[C:4]([N+:1]([O-:3])=[O:2])[CH:12]=[CH:11][CH:10]=2)[C:6](=[O:8])[O:15]1

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 114584612-Acetyl-6-nitrobenzoic acid

Product 1

HCID 18763752HCID 18763752, compoundYield 98.6%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

10.0 g (48 mmol) of 2-nitro-6-acetyl-benzoic acid (cf. Horii et al., Yakugaku Zasshi, 1954, 466, and Baker et al., J. Org. Chem. 1952, 17, 164) are dissolved at 40° C. in 50 ml of 2N sodium hydroxide solution and treated with 1.87 g (48 mmol) of sodium borohydride in portions. After 40 minutes, the reaction mixture, which has been cooled, is acidified and the precipitated crystals are filtered off and dried in vacuo; the product consists of 8.4 g of a product mixture of 82% of 2-nitro-6-(1-hydroxyethyl)-benzoic acid; 1H-NMR (DMSO-D6): 8.00 ppm, m, 2H; 7.68 ppm, t, 1H; 5.6 ppm, b, OH; 4.92 ppm, q, 1H; 1.32 ppm, d, 3H; and 18% of 3-methyl-7-nitro-3H-isobenzofuran-1-one; 1H-NMR (DMSO-D6): 8.02 ppm, m, 2H; 7.68 ppm, t, 1H; 5.80 ppm, q, 1H; 1.62 ppm, d, 3H. The acid aqueous phase is then also extracted with ethyl acetate, combined with the crystals obtained above, dried thoroughly over magnesium sulfate and concentrated completely to dryness by evaporation. 9.14 g (98.6%) of pure 3-methyl-7-nitro-phthalide (3-methyl-7-nitro-3H-isobenzofuran-1-one) are thereby obtained; 1H-NMR (CDCl3): 7.92 ppm, d, 1H; 7.88 ppm, t, 1H; 7.72 ppm, d, 1H; 5.63 ppm, q, 1H; 1.72 ppm, d, 3H.

Workup

  1. temperaturethe reaction mixture, which has been cooled
  2. filtrationthe precipitated crystals are filtered off
  3. customdried in vacuo
  4. additionthe product consists of 8.4 g of a product mixture of 82% of 2-nitro-6-(1-hydroxyethyl)-benzoic acid
  5. extractionThe acid aqueous phase is then also extracted with ethyl acetate
  6. customobtained above,
  7. dry with materialdried thoroughly over magnesium sulfate
  8. concentrationconcentrated completely to dryness by evaporation

Sources & evidence

ORD record
ord-bae634e309444c5190c6534d3171f58a
Source dataset
uspto-grants-2003_12
Patent number
US06657085B2

Reaction notes

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