Xanthone → 2-Iodoxanthen-9-one

HRID 902986

Reaction equation

HRID 902986 reaction equation
[CH:1]1[C:14]2[C:13](=[O:15])[C:12]3[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=3)[O:6][C:5]=2[CH:4]=[CH:3][CH:2]=1.[I:16]N1C(=O)CCC1=O>FC(F)(F)C(O)=O.C(Cl)Cl>[I:16][C:2]1[CH:3]=[CH:4][C:5]2[O:6][C:7]3[C:12](=[CH:11][CH:10]=[CH:9][CH:8]=3)[C:13](=[O:15])[C:14]=2[CH:1]=1

Participants

4

Reactant 2

HCID 7020XanthoneHCID 120273N-Iodosuccinimide

Product 1

HCID 139791862-Iodoxanthen-9-oneYield 54.3%

Reagents, catalysts & solvents 1

HCID 21863450Trifluoroacetic acid methylene chlorideSolvent

Procedure

A solution of xanthen-9-one (1.96 g, 10.0 mmol; Aldrich) in trifluoroacetic acid-CH2Cl2 (1:1, 40 mL) was chilled to 0° C. and treated with N-iodosuccinimide (NIS; 2.25 g, 10.0 mmol; Lancaster), added portionwise over 1 h. After an additional 1 h at 0° C., the ice bath was removed and stirring continued for 8 h. Residual oxidant was quenched with aq. NaS2O3 and the mixture was extracted with CH2Cl2. The organic phase was washed with NaHCO3, dried over MgSO4, and the residue purified by flash chromatography (120 g silica gel, 10-100% CH2Cl2-hexanes) to afford the title compound (1.75 g, 5.43 mmol; 54% yield): 1H NMR (300 MHz, CDCl3) δ ppm 8.66 (d, J=2 Hz, 1H), 8.34 (dd, J=8, 2 Hz, 1H), 7.98 (dd, J=9, 2 Hz, 1H), 7.75 (ddd, J=9, 7, 2 Hz, 1H), 7.50 (dd, J=8, 1 Hz, 1H), 7.40 (ddd, J=8, 7, 1 Hz, 1H), 7.28 (d, J=9 Hz, 1H); MS (DCl/NH3) m/z 323 (M+H)+, 340 (M+NH4)+.

Workup

  1. additionadded portionwise over 1 h
  2. customthe ice bath was removed
  3. waitcontinued for 8 h
  4. customResidual oxidant was quenched with aq. NaS2O3
  5. extractionthe mixture was extracted with CH2Cl2
  6. washThe organic phase was washed with NaHCO3
  7. dry with materialdried over MgSO4
  8. customthe residue purified by flash chromatography (120 g silica gel, 10-100% CH2Cl2-hexanes)

Sources & evidence

ORD record
ord-b0ed738b58704a9c8e0d1ec1ecdc8e14
Source dataset
uspto-grants-2008_04
Patent number
US07365193B2

Linked notes

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