Hydrochloric Acid → 6-Nitro-1-benzofuran-2-carboxylic acid

HRID 1691616Notes

Reaction equation

HRID 1691616 reaction equation
[OH:1][C:2]1[CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=[CH:6][C:3]=1[CH:4]=O.C(=O)([O-])[O-].[K+].[K+].Cl[CH2:20][C:21]([O:23]C)=[O:22].[OH-].[K+].Cl>[I-].C([N+](CCCC)(CCCC)CCCC)CCC.O.C1COCC1>[N+:10]([C:8]1[CH:7]=[CH:6][C:3]2[CH:4]=[C:20]([C:21]([OH:23])=[O:22])[O:1][C:2]=2[CH:9]=1)([O-:12])=[O:11]

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 7295Methyl chloroacetateHCID 11430Potassium CarbonateHCID 14797Potassium HydroxideHCID 755702-Hydroxy-4-nitrobenzaldehyde

Product 1

HCID 131907266-Nitro-1-benzofuran-2-carboxylic acid

Reagents, catalysts & solvents 3

HCID 67553Tetrabutylammonium IodideCatalystHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
130 °C

Procedure

5.8 g (34.7 mmol) of 2-hydroxy-4-nitrobenzaldehyde, 1.28 g (3.5 mmol) of tetrabutylammonium iodide and 19.2 g (138.8 mmol) of potassium carbonate are mixed, 7.9 g (72.9 mmol) of methyl chloroacetate are added, and the mixture is heated at 130° C. for 12 h. 100 ml of THF are added and, while cooling in ice, 11.7 g (208.2 mmol) of potassium hydroxide are added. Addition of 100 ml of water is followed by stirring at room temperature for 20 h. The pH is adjusted to pH 1 with conc. hydrochloric acid. The mixture is extracted with ethyl acetate. The organic phase is washed with water and dried over sodium sulfate. Addition of silica gel is followed by concentration and chromatography on silica gel (mobile phase: toluene/methanol/acetic acid). Concentration of the product fractions and drying in vacuo result in 1.31 g (18.2% of theory) of the title compound.

Workup

  1. temperaturewhile cooling in ice
  2. extractionThe mixture is extracted with ethyl acetate
  3. washThe organic phase is washed with water
  4. dry with materialdried over sodium sulfate
  5. additionAddition of silica gel
  6. concentrationis followed by concentration and chromatography on silica gel (mobile phase: toluene/methanol/acetic acid)
  7. customConcentration of the product fractions and drying in vacuo

Sources & evidence

ORD record
ord-1d4d684558834829a5c5971cd60eb99c
Source dataset
uspto-grants-2012_04
Patent number
US08153799B2

Reaction notes

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