Sulfolane → Benzene, 1-chloro-2,3-difluoro-5-(trifluoromethyl)-

HRID 280727Notes

Reaction equation

HRID 280727 reaction equation
[F-:1].[K+].[Cl:3][C:4]1[CH:5]=[C:6]([C:12]([F:15])([F:14])[F:13])[CH:7]=[C:8](Cl)[C:9]=1[F:10].S1(CCCC1)(=O)=O>>[Cl:3][C:4]1[CH:5]=[C:6]([C:12]([F:15])([F:14])[F:13])[CH:7]=[C:8]([F:1])[C:9]=1[F:10]

Participants

4

Reactant 3

HCID 31347SulfolaneHCID 157026Benzene, 1,3-dichloro-2-fluoro-5-(trifluoromethyl)-HCID 522689Potassium Fluoride

Product 1

HCID 2736496Benzene, 1-chloro-2,3-difluoro-5-(trifluoromethyl)-

Procedure

A mixture of 55 parts of anhydrous potassium fluoride and 45.32 parts of 3,5-dichloro-4-fluorobenzotrifluoride in 291 parts of sulfolane was heated and maintained at about 216° to 256° for a period of about 55 hours, while product vapors were removed through a distillation column at a head temperature of about 130°-150° C. A total of 32.02 parts of distillate was collected and analyzed by gas chromatography/mass spectrometry. The distillate was found to be 25.1 percent 3,5-dichloro-4-fluorobenzotrifluoride; 65.9 percent 3-chloro-4,5-difluorobenzotrifluoride; 8.6 percent 3,4,5-trifluorobenzotrifluoride and trace amounts of 4-chloro-3,5-difluorobenzotrifluoride. The desired 3-chloro-4,5-difluorobenzotrifluoride was isolated by distillation (b.p. 122° C.) to recover it in essentially pure form (greater than 99 percent pure). The 3,5-dichloro-4-fluoro isomer is recycled.

Workup

  1. temperaturewas heated
  2. temperaturemaintained at about 216° to 256° for a period of about 55 hours, while product vapors
  3. customwere removed through a distillation column at a head temperature of about 130°-150° C
  4. distillationA total of 32.02 parts of distillate was collected

Sources & evidence

ORD record
ord-c6787f22a7ef4c1083fa9abc315968bb
Source dataset
uspto-grants-1986_05
Patent number
US04590315

Reaction notes

Loading…