Phosphorus pentachloride → 3-Iodo-4-methoxybenzoyl chloride

HRID 1976349Notes

Reaction equation

HRID 1976349 reaction equation
P(Cl)(Cl)(Cl)(Cl)[Cl:2].[I:7][C:8]1[CH:9]=[C:10]([CH:14]=[CH:15][C:16]=1[O:17][CH3:18])[C:11](O)=[O:12]>C(Cl)(Cl)Cl>[I:7][C:8]1[CH:9]=[C:10]([CH:14]=[CH:15][C:16]=1[O:17][CH3:18])[C:11]([Cl:2])=[O:12]

Participants

4

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 6241583-Iodo-4-methoxybenzoic acid

Product 1

HCID 118333813-Iodo-4-methoxybenzoyl chlorideYield 85.5%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

To a suspension of PCl5 (33.0 g, 158 mmol) in 30 mL CHCl3 was added, with magnetic stirring, 3-iodo-p-anisic acid (40.0 g, 144 mmol) in small portions. The solution was heated at reflux for b 1 h under a gentle nitrogen sweep, during which time the solution became homogenous. The solvent was evaporated under reduced pressure, then the residue was distilled under high vacuum. The fraction distilling at 152-156° C. (5 mm Hg; lit.10 bp 183-185° C., 12-13 mm Hg) was collected, which rapidly solidified as a pink solid. Recrystallization from 200 mL hexane/CH2Cl2 afforded the desired product as white needles (36.4 g, 85.5%); mp 58° C.; 1H NMR (CDCl3) δ 3.99 (s, 3 H), 6.88 (d, 1 H, J=8.7 Hz), 8.13 (dd, 1 H, J=8.7, 2.4 Hz), 8.52 (d, 1 H, J=2.4 Hz); EI-MS m/z 296 (M+, 42), 261 (100).

Workup

  1. temperatureThe solution was heated
  2. temperatureat reflux for b 1 h under a gentle nitrogen
  3. customThe solvent was evaporated under reduced pressure
  4. distillationthe residue was distilled under high vacuum
  5. distillationThe fraction distilling at 152-156° C. (5 mm Hg; lit.10 bp 183-185° C., 12-13 mm Hg)
  6. customwas collected
  7. customRecrystallization from 200 mL hexane/CH2Cl2

Sources & evidence

ORD record
ord-bccfe2d666134561b380adedbf6cf837
Source dataset
uspto-grants-2001_05
Patent number
US06225481B1

Reaction notes

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