Thionyl Chloride → 3,5-Diiodobenzonitrile

HRID 56070Notes

Reaction equation

HRID 56070 reaction equation
S(Cl)(Cl)=O.[I:5][C:6]1[CH:7]=[C:8]([CH:12]=[C:13]([I:15])[CH:14]=1)[C:9]([NH2:11])=O>>[I:5][C:6]1[CH:7]=[C:8]([CH:12]=[C:13]([I:15])[CH:14]=1)[C:9]#[N:11]

Participants

3

Procedure

To a stirred solution of 3,5-diiodbenzoic acid (1.7 g, 4.5 mmol) in dichloromethane (DCM; 10 mL) was added oxalyl chloride (2.9 g, 23 mmol). After 5 hours, the volatile contents were removed under reduced pressure. The resulting residue was poured with caution into cold ammonium hydroxide (50 mL, 28%) and stirred for 2 h. The amide product was removed by filtration and the collected residue was dissolved in DCM and washed with 1 M HCl, 1 M NaOH, water and brine. The organic layer was dried with MgSO4. Removal of DCM in vacuo afforded 3,5-diiodobenzamide which was used without further purification. Thionyl chloride (8.2 g, 69 mmol) was added to the collected amide and the mixture was heated under reflux for 18 h. The reaction mixture was allowed to cool and excess thionyl chloride removed under reduced pressure. The resulting residue was dissolved in EtOAc and washed with a saturated solution of NaHCO3 (3×10 mL), water (2×10 mL), brine and dried over anhydrous MgSO4. Concentration of the organic solution followed by column chromatography purification yielded the titled compound as an off white solid in 60% yield; mp 129-131° C.; 1H-NMR (300 MHz, CDCl3) δ (ppm): δ 8.30 (t, J=1.4 Hz, 1H), 7.94 (d, J=1.5 Hz, 2H). 13C-NMR (75 MHz, CDCl3) δ (ppm): 149.7, 139.6, 115.6, 115.5, 94.5 HRMS (m/z): [M+H]+ calc. for C7H4I2N, 355.8428. found 355.8439.

Workup

  1. customwas used without further purification
  2. temperaturethe mixture was heated
  3. temperatureunder reflux for 18 h
  4. temperatureto cool
  5. customexcess thionyl chloride removed under reduced pressure
  6. dissolutionThe resulting residue was dissolved in EtOAc
  7. washwashed with a saturated solution of NaHCO3 (3×10 mL), water (2×10 mL), brine
  8. dry with materialdried over anhydrous MgSO4
  9. customConcentration of the organic solution followed by column chromatography purification

Sources & evidence

ORD record
ord-bee530a10cda4f4d9d0c6580bd3460bb
Source dataset
uspto-grants-2016_09
Patent number
US09434699B2

Reaction notes

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