1,2-Dichlorobenzene → 2-Fluoro-3,4-dimethylbenzaldehyde

HRID 380084Notes

Reaction equation

HRID 380084 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].ClC1C=CC=CC=1Cl.[F:13][C:14]1[CH:19]=[CH:18][CH:17]=[C:16]([CH3:20])[C:15]=1[CH3:21].FC1C=CC([CH:27]=[O:28])=C(C)C=1C>Cl>[F:13][C:14]1[C:15]([CH3:21])=[C:16]([CH3:20])[CH:17]=[CH:18][C:19]=1[CH:27]=[O:28]

Participants

6

Reactant 4

HCID 72391,2-DichlorobenzeneHCID 964893-Fluoro-o-xyleneHCID 6451240Aluminum(III) ChlorideHCID 120407124-Fluoro-2,3-dimethylbenzaldehyde

Product 1

HCID 120407132-Fluoro-3,4-dimethylbenzaldehydeYield 79.1%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidCatalyst

Conditions

Temperature
50 °C

Procedure

67.60 g of aluminum chloride (mol. Wt. 133.34; 507.0 mmol), 450.0 g of 1,2-dichlorobenzene (mol. Wt. 147.00; 3,061 mmol), and about 503.54 g of 3-fluoro-o-xylene (mol. Wt. 124.16; 789.3 mmol) were charged to a 2 liter Parry -brand 4522 stainless steel reaction vessel. To this mixture was added 5 drops of concentrated HCl. The vessel was sealed, heated to 50° 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 200 psi, the pressure at which the reaction was maintained for the total reaction time of about 28 hours (the reaction temperature was maintained at 50° 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, 3-fluoro-o-xylene, 1,2-dichlorobenzene, and left about 94.98 g of a benzaldehyde mixture consisting of 4-fluoro-2,3-dimethylbenzaldehyde (89.1 %) and 2-fluoro-3,4-dimethylbenzaldehyde (10.9%) (mol. Wt. 152.17; 624.2 mmol; yield of approximately 79.1%).

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 28 hours (the reaction temperature
  6. temperaturewas maintained at 50° 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, 3-fluoro-o-xylene, 1,2-dichlorobenzene
  14. waitleft about 94.98 g of a benzaldehyde mixture

Sources & evidence

ORD record
ord-defc05cf223e401bb68a3338806d2ecc
Source dataset
uspto-grants-2001_10
Patent number
US06300525B1

Reaction notes

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