Potassium Iodide → 5-Iodo-3-methyl-2,3-dihydro-1,3-benzoxazol-2-one

HRID 2386809Notes

Reaction equation

HRID 2386809 reaction equation
N([O-])=O.[Na+].N[C:6]1[CH:7]=[CH:8][C:9]2[O:13][C:12](=[O:14])[N:11]([CH3:15])[C:10]=2[CH:16]=1.[I-:17].[K+].S(S([O-])=O)([O-])(=O)=O.[Na+].[Na+]>O.C(O)(=O)C>[I:17][C:6]1[CH:7]=[CH:8][C:9]2[O:13][C:12](=[O:14])[N:11]([CH3:15])[C:10]=2[CH:16]=1

Participants

7

Reactant 4

HCID 4875Potassium IodideHCID 656671Sodium PyrosulfiteHCID 235056635-Amino-3-methyl-2,3-dihydro-1,3-benzoxazol-2-oneHCID 23668193Sodium Nitrite

Product 1

HCID 666970225-Iodo-3-methyl-2,3-dihydro-1,3-benzoxazol-2-oneYield 55.8%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent2×

Procedure

A solution of sodium nitrite (4.62 g) in water (40 mL) was added dropwise over a period of 15 minutes at 0° C. to a solution of 5-amino-3-methyl-3H-benzooxazol-2-one (10 g) in acetic acid (400 mL). Stirring was continued for 10 minutes at 0° C. A solution of potassium iodide (11.12 g) in water (40 mL) was added dropwise over a period of 15 minutes. Stirring was continued for 1 hour at 0° C. Sodium pyrosulfite (1.0 g) was added to the reaction mixture. Stirring was continued for 10 minutes. The reaction mixture was then evaporated to dryness. The residue was dissolved in CH2Cl2 and the solution was poured into sat. Na2CO3 (pH 9) and 0.2 M sodium pyrosulfite solution and extracted two times with CH2Cl2. The combined organic layers were washed with brine, dried over Na2SO4, filtered and the solvent was evaporated. The residue was purified by flash chromatography (silica gel, gradient of heptane in ethyl acetate) to give the title compound as a colorless solid (9.35 g, 55%). MS (m/e)=275.9 [M+H+].

Workup

  1. stirringStirring
  2. waitwas continued for 1 hour at 0° C
  3. stirringStirring
  4. waitwas continued for 10 minutes
  5. customThe reaction mixture was then evaporated to dryness
  6. dissolutionThe residue was dissolved in CH2Cl2
  7. additionthe solution was poured into sat. Na2CO3 (pH 9) and 0.2 M sodium pyrosulfite solution
  8. extractionextracted two times with CH2Cl2
  9. washThe combined organic layers were washed with brine
  10. dry with materialdried over Na2SO4
  11. filtrationfiltered
  12. customthe solvent was evaporated
  13. customThe residue was purified by flash chromatography (silica gel, gradient of heptane in ethyl acetate)

Sources & evidence

ORD record
ord-5c123fa5a408439889c20f1a415651d2
Source dataset
uspto-grants-2012_09
Patent number
US08268820B2

Reaction notes

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