Hydrochloric Acid → 1-Methyl-5-(2-fluorobenzoyl)-1,2,3,4-tetrahydroquinoxaline

HRID 1109720Notes

Reaction equation

HRID 1109720 reaction equation
B(Cl)(Cl)Cl.[CH3:5][N:6]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[NH:9][CH2:8][CH2:7]1.[F:16][C:17]1[CH:24]=[CH:23][CH:22]=[CH:21][C:18]=1[C:19]#N.[Cl-].[Cl-].[Cl-].[Al+3].Cl.C(OCC)(=[O:32])C>C1C=CC=CC=1.C1(C)C=CC=CC=1.O>[CH3:5][N:6]1[C:15]2[C:10](=[C:11]([C:19](=[O:32])[C:18]3[CH:21]=[CH:22][CH:23]=[CH:24][C:17]=3[F:16])[CH:12]=[CH:13][CH:14]=2)[NH:9][CH2:8][CH2:7]1

Participants

10

Reactant 6

HCID 313Hydrochloric AcidHCID 8857Ethyl AcetateHCID 25135Boron TrichlorideHCID 678552-FluorobenzonitrileHCID 2158501-Methyl-1,2,3,4-tetrahydroquinoxalineHCID 6451240Aluminum(III) Chloride

Product 1

HCID 102651411-Methyl-5-(2-fluorobenzoyl)-1,2,3,4-tetrahydroquinoxaline

Reagents, catalysts & solvents 3

HCID 241BenzeneSolventHCID 962WaterSolventHCID 1140TolueneSolvent2×

Procedure

To a solution of 2N-boron trichloride in benzene (82 ml) was dropwise added a solution of 1-methyl-1,2,3,4-tetrahydroquinoxaline (19.87 g) in toluene (40 ml) under stirring. To the resultant mixture was dropwise added a solution of 2-fluorobenzonitrile (19.50 g) in toluene (30 ml) at ambient temperature under stirring and the mixture was stirred for 1.5 hours under the same condition. To this mixture was added aluminum trichloride (19.65 g) and the mixture was refluxed for 16 hours. Water (30 ml) and 2N-hydrochloric acid (100 ml) were added to the reaction mixture under cooling in an ice-bath and the mixture was refluxed for 2.5 hours. After the mixture was allowed to stand at ambient temperature for several hours, ethyl acetate was added to the mixture. The organic layer was separated, washed with water twice, dried over magnesium sulfate and evaporated under reduced pressure. The residue was chromatographed on silica gel with an eluent of n-hexane. The fractions containing the desired product were combined and evaporated. The resultant red oil was crystallized with diisopropyl ether, collected by filtration and dried to give 1-methyl-5-(2-fluorobenzoyl)-1,2,3,4-tetrahydroquinoxaline (11.71 g).

Workup

  1. stirringunder stirring
  2. stirringthe mixture was stirred for 1.5 hours under the same condition
  3. temperaturethe mixture was refluxed for 16 hours
  4. temperatureunder cooling in an ice-bath
  5. temperaturethe mixture was refluxed for 2.5 hours
  6. waitto stand at ambient temperature for several hours
  7. customThe organic layer was separated
  8. washwashed with water twice
  9. dry with materialdried over magnesium sulfate
  10. customevaporated under reduced pressure
  11. customThe residue was chromatographed on silica gel with an eluent of n-hexane
  12. additionThe fractions containing the desired product
  13. customevaporated
  14. customThe resultant red oil was crystallized with diisopropyl ether
  15. filtrationcollected by filtration
  16. customdried

Sources & evidence

ORD record
ord-2565d433ff0f497dbc2588c7c291b759
Source dataset
uspto-grants-1994_06
Patent number
US05322842

Reaction notes

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