Phosphorus pentachloride → 4-Cyclopropyl-2-methylbenzoyl chloride

HRID 2245727Notes

Reaction equation

HRID 2245727 reaction equation
[CH:1]1([C:4]2[CH:12]=[CH:11][C:7]([C:8](O)=[O:9])=[C:6]([CH3:13])[CH:5]=2)[CH2:3][CH2:2]1.P(Cl)(Cl)(Cl)(Cl)[Cl:15]>>[CH:1]1([C:4]2[CH:12]=[CH:11][C:7]([C:8]([Cl:15])=[O:9])=[C:6]([CH3:13])[CH:5]=2)[CH2:3][CH2:2]1

Participants

3

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 590206584-Cyclopropyl-2-methylbenzoic acid

Product 1

HCID 592165404-Cyclopropyl-2-methylbenzoyl chlorideYield 95.8%

Procedure

4-Cyclopropyl-2-methylbenzoic acid (25.01 g, 142 mmol) and phosphorus pentachloride (32.84 g, 158 mmol) were charged into a 100 mL round bottom flask fitted with a stir bar, reflux condenser, and calcium chloride drying tube exhausted through a dilute aqueous solution of NaOH as a gas trap. Refluxed the mixture at a bath temperature of 120° for 2 hr. Removed the POCl3 byproduct by distillation at atmospheric pressure. Vacuum distilled the residue. Collected the fraction distilling at 116-118°/3 torr to obtain 4-cyclopropyl-2-methylbenzoyl chloride as a clear colorless liquid (26.39 g, 136 mmol). 1H NMR (300 MHz, chloroform-d) ppm 0.77-0.86 (m, 2H) 1.06-1.16 (m, 2H) 1.87-1.99 (m, 1H) 2.54 (s, 3H) 6.93-7.03 (m, 2H) 8.14 (d, J=8.29 Hz, 1H).

Workup

  1. customfitted with a stir bar
  2. temperaturereflux condenser, and calcium chloride drying tube
  3. customexhausted through a dilute aqueous solution of NaOH as a gas trap
  4. temperatureRefluxed the mixture at a bath temperature of 120° for 2 hr
  5. customRemoved the POCl3 byproduct
  6. distillationby distillation at atmospheric pressure
  7. distillationVacuum distilled the residue
  8. customCollected the fraction
  9. distillationdistilling at 116-118°/3 torr

Sources & evidence

ORD record
ord-a9ab5b82dc15436f89a12cbe3e2f6334
Source dataset
uspto-grants-2010_03
Patent number
US07683064B2

Reaction notes

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