Citric Acid → HCID 19780736, compound

HRID 2081801Notes

Reaction equation

HRID 2081801 reaction equation
[N+:1]([CH3:4])([O-:3])=[O:2].CC(C)([O-])C.[K+].[CH3:11][C:12]1[O:13][C:14]2[C:19]([C:20](=[O:23])[C:21]=1[CH3:22])=[CH:18][C:17]([S:24]([O-])(=[O:26])=[O:25])=[CH:16][CH:15]=2.[Na+].II.C(O)(=O)CC(CC(O)=O)(C(O)=O)O.S(S([O-])=O)([O-])(=O)=O.[Na+].[Na+]>CN(C)C=O.O.C1(C)C=CC=CC=1>[CH3:11][C:12]1[O:13][C:14]2[C:19]([C:20](=[O:23])[C:21]=1[CH3:22])=[CH:18][C:17]([S:24]([CH2:4][N+:1]([O-:3])=[O:2])(=[O:25])=[O:26])=[CH:16][CH:15]=2

Participants

10

Reactant 6

HCID 311Citric AcidHCID 807IodineHCID 6375NitromethaneHCID 656671Sodium PyrosulfiteHCID 23665647Potassium tert-butoxideHCID 23716505HCID 23716505, compound

Product 1

HCID 19780736HCID 19780736, compoundYield 7.5%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 1140TolueneSolventHCID 6228DimethylformamideSolvent

Procedure

Nitromethane (0.92 ml, 17 mmol) was added dropwise to a stirred solution of potassium t-butoxide (0.84 g, 8.4 mM) in N,N-dimethylformamide (DMF; 40 ml) at -5° C. When the addition was complete, stirring was continued for 30 minutes at -5° C. Sodium 2,3-dimethyl-4-oxo-4H-chromene-6-sulphonate (2.2 g, 8.5 mM) was then added, followed immediately by iodine (1.07 g, 4.2 mM). The mixture was allowed to attain ambient temperature and stirred overnight. The reaction mixture was then added to a solution of citric acid (15 g) and sodium metabisulphite (3 g) in water (150 ml). The aqueous mixture was extracted with dichloromethane (3×50 ml) and the combined organic extracts were washed with sodium chloride solution. The solvent was removed by evaporation and the residual semi-solid purified by flash vacuum chromatography on silica, eluting with ethyl acetate/hexane (1:1 v/v), to give 2,3-dimethyl-6-(nitromethyl-sulphonyl)-4H-chromen-4-one as a solid (178 mg, 7.1% yield), m.p. 206°-209° C. [after recrystallisation from toluene]; NMR (d6DMSO): 2.0(3H,s), 2.45(3H,s), 7.5(2H,s), 7.75(1H,d), 8.1(1H,dd), 8.45(1H,d); microanalysis, found: C,49.0; H,3.6; N,4.7%; C12H11NO6S requires: C,48.5; H,3.6; N,4.7%.

Workup

  1. additionWhen the addition
  2. customto attain ambient temperature
  3. stirringstirred overnight
  4. extractionThe aqueous mixture was extracted with dichloromethane (3×50 ml)
  5. washthe combined organic extracts were washed with sodium chloride solution
  6. customThe solvent was removed by evaporation
  7. customthe residual semi-solid purified by flash vacuum chromatography on silica
  8. washeluting with ethyl acetate/hexane (1:1 v/v)
  9. customto give

Sources & evidence

ORD record
ord-63e7d893ce3d47b28481b9b32c791efb
Source dataset
uspto-grants-1993_02
Patent number
US05185452

Reaction notes

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