Hydrochloric Acid → 7-Nitro-benzofuran-2-carboxylic acid

HRID 335575Notes

Reaction equation

HRID 335575 reaction equation
O[C:2]1[CH:9]=[CH:8][C:7]([N+:10]([O-:12])=[O:11])=[CH:6][C:3]=1[CH:4]=O.[C:13](=[O:16])([O-])[O-:14].[K+].[K+].ClC[C:21](OC)=[O:22].[OH-].[K+].Cl>O.C1COCC1>[N+:10]([C:7]1[C:6]2[O:22][C:21]([C:13]([OH:14])=[O:16])=[CH:4][C:3]=2[CH:2]=[CH:9][CH:8]=1)([O-:12])=[O:11]

Participants

8

Reactant 5

HCID 313Hydrochloric AcidHCID 7295Methyl chloroacetateHCID 11430Potassium CarbonateHCID 14797Potassium HydroxideHCID 668085-Nitrosalicylaldehyde

Product 1

HCID 593413787-Nitro-benzofuran-2-carboxylic acid

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
130 °C

Procedure

3.0 g (17.9 mmol) of 2-hydroxy-5-nitrobenzaldehyde, 0.66 g (1.80 mmol) of tetra-N-butylammonium iodide and 9.92 g (71.81 mmol) of potassium carbonate are mixed, 4.09 g (37.7 mmol) of methyl chloroacetate are added and the mixture is heated at 130° C. for 4 h. 35 ml of THF and, with ice cooling, 6.04 g (107.71 mmol) of potassium hydroxide are added. Following the addition of 50 ml of water, the mixture is stirred at RT for 20 h. Using concentrated hydrochloric acid, the pH is adjusted to 0. The mixture is extracted with ethyl acetate. The organic phase is washed with water and dried over sodium sulfate. After the addition of silica gel, the mixture is concentrated and chromatographed on silica gel (mobile phase gradient: toluene to toluene/methanol/glacial acetic acid 35:5:1). Concentration of the product fractions and drying under reduced pressure gives 2.00 g (54% of theory) of the title compound.

Workup

  1. extractionThe mixture is extracted with ethyl acetate
  2. washThe organic phase is washed with water
  3. dry with materialdried over sodium sulfate
  4. additionAfter the addition of silica gel
  5. concentrationthe mixture is concentrated
  6. customchromatographed on silica gel (mobile phase gradient: toluene to toluene/methanol/glacial acetic acid 35:5:1)
  7. customConcentration of the product fractions and drying under reduced pressure

Sources & evidence

ORD record
ord-a57b49bc76824dad870a08444427700b
Source dataset
uspto-grants-2014_11
Patent number
US08884017B2

Reaction notes

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