1,1'-Carbonyldiimidazole → 7-Iodo-5-nitro-1,3-benzoxazol-2(3H)-one

HRID 542028Notes

Reaction equation

HRID 542028 reaction equation
O[C:2]1[C:7]([I:8])=[CH:6][C:5]([N+:9]([O-:11])=[O:10])=[CH:4][C:3]=1[NH:12][C:13](=[O:19])[O:14]C(C)(C)C.C1N=CN(C(N2C=NC=C2)=O)C=1>C1COCC1>[I:8][C:7]1[C:2]2[O:19][C:13](=[O:14])[NH:12][C:3]=2[CH:4]=[C:5]([N+:9]([O-:11])=[O:10])[CH:6]=1

Participants

4

Reactant 2

HCID 682631,1'-CarbonyldiimidazoleHCID 57961943Tert-butyl (2-hydroxy-3-iodo-5-nitrophenyl)carbamate

Product 1

HCID 579620517-Iodo-5-nitro-1,3-benzoxazol-2(3H)-oneYield 716.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of tert-butyl (2-hydroxy-3-iodo-5-nitrophenyl)carbamate (1.0 g, 2.6 mmol) and N,N-carbonyldiimidazole (0.47 g, 2.9 mmol) in THF (6 mL) was stirred at reflux for 1 h. The reaction mixture was concentrated, diluted with ethyl acetate (100 mL), washed with 1 N HCl (50 mL), water (20 mL), and brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to give a crude solid. This material was concentrated from hexanes (2×) to give the desired product (5.7 g, 91%) as an orange solid. This material was purified by flash column chromatography to give the desired product (0.66 g, 82%) as a yellow solid. LCMS for C7H41N2O4 (M+H)+: m/z=306.8.

Workup

  1. temperatureat reflux for 1 h
  2. concentrationThe reaction mixture was concentrated
  3. additiondiluted with ethyl acetate (100 mL)
  4. washwashed with 1 N HCl (50 mL), water (20 mL), and brine (20 mL)
  5. dry with materialdried over anhydrous sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customto give a crude solid
  9. concentrationThis material was concentrated from hexanes (2×)

Sources & evidence

ORD record
ord-23dd2e81159549a2b6380bc9080bf78c
Source dataset
uspto-grants-2014_10
Patent number
US08871753B2

Reaction notes

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