Diethyl Ether → 6-Iodo-2,3-dihydro-1,3-benzoxazol-2-one

HRID 502192Notes

Reaction equation

HRID 502192 reaction equation
[I:1][C:2]1[CH:3]=[C:4]([OH:11])[C:5](=[CH:9][CH:10]=1)C(O)=O.CC[N:14]([CH2:17]C)CC.C1C=CC(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:26])=CC=1.CCOCC>C1COCC1>[I:1][C:2]1[CH:10]=[CH:9][C:5]2[NH:14][C:17](=[O:26])[O:11][C:4]=2[CH:3]=1

Participants

6

Reactant 4

HCID 3283Diethyl EtherHCID 8471TriethylamineHCID 728742-Hydroxy-4-iodobenzoic acidHCID 199401P,P-Diphenylphosphinic azide

Product 1

HCID 120323716-Iodo-2,3-dihydro-1,3-benzoxazol-2-oneYield 37.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
70 °C

Procedure

Crude 4-Iodosalicylic acid (1.0 g, 3.8 mmol) is dissolved in THF (28 mL) and Et3N (1.15 mL, 8.2 mmol). DPPA (1.7 mL, 7.8 mmol) is added. This is heated at 70° C. overnight. The reaction mixture is then partitioned between H2O and EtOAc. The organic layer is dried and concentrated. Purification by silica gel chromatography (9/1, CH2Cl2/EtOAc) yields 472 mg crude intermediate. Trituration with ether yields 6-iodo-3H-benzooxazol-2-one (369 mg, 37%) as a white solid.

Workup

  1. customThe reaction mixture is then partitioned between H2O and EtOAc
  2. customThe organic layer is dried
  3. concentrationconcentrated
  4. customPurification by silica gel chromatography (9/1, CH2Cl2/EtOAc)
  5. customyields 472 mg crude intermediate

Sources & evidence

ORD record
ord-56979d1a500144a185ee8c7998469e7d
Source dataset
uspto-grants-2010_08
Patent number
US07772271B2

Reaction notes

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