Hydrochloric Acid → 2-Chloro-5-(trifluoromethyl)benzaldehyde

HRID 1388533Notes

Reaction equation

HRID 1388533 reaction equation
N[C:2]1[CH:3]=[C:4]([C:9]([F:12])([F:11])[F:10])[CH:5]=[CH:6][C:7]=1[Cl:8].Cl.N([O-])=O.[Na+].O.O.O.[C:21]([O-])(=[O:23])C.[Na+].C=O.Cl.NO.[Na].S([O-])([O-])=O.C([O-])(=O)C.[Na+]>O.C1(C)C=CC=CC=1>[Cl:8][C:7]1[CH:6]=[CH:5][C:4]([C:9]([F:12])([F:11])[F:10])=[CH:3][C:2]=1[CH:21]=[O:23]

Participants

12

Reactant 9

HCID 313Hydrochloric Acid3×HCID 712FormaldehydeHCID 1099SulfiteHCID 8475Benzenamine, 2-chloro-5-(trifluoromethyl)-HCID 443297Hydroxyamine hydrochlorideHCID 517045Sodium AcetateHCID 5360545SodiumHCID 23665404Sodium Acetate Trihydrate2×HCID 23668193Sodium Nitrite

Product 1

HCID 6881812-Chloro-5-(trifluoromethyl)benzaldehydeYield 32%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent5×HCID 1140TolueneSolvent

Procedure

3-Amino-4-chlorobenzotrifluoride (A.E. Porai-Kosic et al., Zh. Prikl. Khim. 28, 969, 1955; Chem. Abstr. 50, 4880, 1956) (222 g) is slowly added to a stirred solution of 260 ml hydrochloric acid in 2330 ml water. The resultant suspension of the hydrochloride is cooled, treated with 450 g of ice and diazotized at 0°-5° C. with a solution of 80 g of sodium nitrite in 110 ml of water, added dropwise. The mixture is stirred for 1 hour at 0°-5° C. and treated with a cooled solution of 100 g of sodium acetate trihydrate in 150 ml water. The undissolved substance is separated (distillation recovers 70.8 g starting 3-amino-4-chlorobenzotrifluoride) and the solution of the diazonium salt is added while stirring at 10°-20° C. to a solution of formaldoxime (prepared by boiling a mixture of 57.5 g paraformaldehyde, 131.5 g of hydroxylamine hydrochloride, 255 g of sodium acetate trihydrate and 850 ml of water for 15 minutes) and a solution of 32.5 g cupric sulfate pentahydrate, 5 g sodium of sulfite and 800 g of sodium acetate in 300 ml water with the addition of 300 ml of toluene. The mixture is stirred for 2 hours, 1100 ml of hydrochloric acid added and the mixture refluxed for 2 hours. It is then distilled with steam and the distillate extracted with benzene. The extract is washed with a 5% sodium hydrogen carbonate solution and evaporated. The residue is dissolved in 200 ml ether and the solution stirred for 2 hours with 450 ml of 40% sodium hydrogen sulfite solution. After standing overnight, the precipitated addition product is filtered with suction, washed with ether, and suspended in 1 liter of water, then, 200 ml of hydrochloric acid are added and the mixture refluxed for 2 hours. After cooling, it is extracted with benzene, the extract dried with magnesium sulfate, evaporated and the residue processed by distillation. There are obtained 49.1 g (31% per conversion) of 2-chloro-5-trifluoromethylbenzaldehyde, b.p. 93°-96° C./2.1 kPa.

Workup

  1. temperatureis cooled
  2. additionadded dropwise
  3. customThe undissolved substance is separated
  4. distillation(distillation recovers 70.8 g starting 3-amino-4-chlorobenzotrifluoride)
  5. additionthe solution of the diazonium salt is added
  6. stirringwhile stirring at 10°-20° C. to a solution of formaldoxime (
  7. customprepared
  8. stirringThe mixture is stirred for 2 hours
  9. temperaturethe mixture refluxed for 2 hours
  10. distillationIt is then distilled with steam
  11. extractionthe distillate extracted with benzene
  12. washThe extract is washed with a 5% sodium hydrogen carbonate solution
  13. customevaporated
  14. dissolutionThe residue is dissolved in 200 ml ether
  15. stirringthe solution stirred for 2 hours with 450 ml of 40% sodium hydrogen sulfite solution
  16. waitAfter standing overnight
  17. additionthe precipitated addition product
  18. filtrationis filtered with suction
  19. washwashed with ether
  20. addition200 ml of hydrochloric acid are added
  21. temperaturethe mixture refluxed for 2 hours
  22. temperatureAfter cooling
  23. extractionit is extracted with benzene
  24. dry with materialthe extract dried with magnesium sulfate
  25. customevaporated
  26. distillationthe residue processed by distillation

Sources & evidence

ORD record
ord-292980b3d8584cc3a1e0343ef764e1a4
Source dataset
uspto-grants-1984_02
Patent number
US04431808

Reaction notes

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