2-Chlorotoluene → 3-Chloro-4-methylbenzaldehyde

HRID 379351Notes

Reaction equation

HRID 379351 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].CC1C=C[C:9]([O:12]C)=CC=1.[Cl:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][C:16]=1[CH3:21].ClC1C=CC(C=O)=CC=1C>Cl>[Cl:14][C:15]1[CH:20]=[C:19]([CH:18]=[CH:17][C:16]=1[CH3:21])[CH:9]=[O:12]

Participants

6

Reactant 4

HCID 72382-ChlorotolueneHCID 77314-MethylanisoleHCID 27576594-Chloro-3-methylbenzaldehydeHCID 6451240Aluminum(III) Chloride

Product 1

HCID 124230853-Chloro-4-methylbenzaldehydeYield 389.3%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidCatalyst

Conditions

Temperature
30 °C

Procedure

216.00 g of aluminum chloride (mol. Wt. 133.34; 1,619.9 mmol), 109.09 g (4-Methylanisole (mol. Wt. 122.17; 892.9 mmol), and about 522.35 g of 2-chlorotoluene (mol. Wt. 126.59; 4,126.3 mmol) were charged to a 2 liter Parr®-brand 4522 stainless steel reaction vessel. To this mixture was added 5 drops of concentrated HCl. The vessel was sealed, heated to 30° C., and purged three times with carbon monoxide with the pressure of the vessel increased to 100 psi for each purging. After the third purge, the vessel was vented and a final introduction of CO was made at a pressure of about 550 psi, the pressure at which the reaction was maintained for the total reaction time of about 66 hours (the reaction temperature was maintained at 30° C. for the duration as well). Once the reaction was complete, the resultant mixture (exhibiting a dark orange color) was poured into about 500 mL of ice water (which turned the solution a yellow color), to which was added 500 mL of cyclohexane. The top, organic layer was removed and washed three times with water using a separatory funnel and dried over magnesium sulfate. The residual organic phase was then distilled under vacuum to remove excess cyclohexane, 2-chlorotoluene, and left about 76.01 g of a benzaldehyde mixture consisting of 4-chloro-3-methylbenzaldehyde (76.5%) and 3-chloro-4-methylbenzaldehyde (23.5%) (mol.wt. 154.59; 491.7 mmol; yield of approximately 67.6%).

Workup

  1. customThe vessel was sealed
  2. custompurged three times with carbon monoxide with the pressure of the vessel
  3. temperatureincreased to 100 psi for each purging
  4. customAfter the third purge
  5. temperaturethe pressure at which the reaction was maintained for the total reaction time of about 66 hours (the reaction temperature
  6. temperaturewas maintained at 30° C. for the duration as well)
  7. additionwas poured into about 500 mL of ice water (which
  8. additionwas added 500 mL of cyclohexane
  9. customThe top, organic layer was removed
  10. washwashed three times with water using a separatory funnel
  11. dry with materialdried over magnesium sulfate
  12. distillationThe residual organic phase was then distilled under vacuum
  13. customto remove excess cyclohexane, 2-chlorotoluene
  14. waitleft about 76.01 g of a benzaldehyde mixture

Sources & evidence

ORD record
ord-1d021d31f510487c837a8e41b3167eca
Source dataset
uspto-grants-2001_10
Patent number
US06297405B1

Reaction notes

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