Boron trifluoride → Methyl 1,2,3,4-tetrahydroquinoline-7-carboxylate

HRID 1808330Notes

Reaction equation

HRID 1808330 reaction equation
B(F)(F)F.[N:5]1[C:14]2[C:9](=[CH:10][CH:11]=[C:12]([C:15]([O:17][CH3:18])=[O:16])[CH:13]=2)[CH:8]=[CH:7][CH:6]=1.C([BH3-])#N.[Na+]>CO>[NH:5]1[C:14]2[C:9](=[CH:10][CH:11]=[C:12]([C:15]([O:17][CH3:18])=[O:16])[CH:13]=2)[CH2:8][CH2:7][CH2:6]1

Participants

5

Reactant 3

HCID 6356Boron trifluorideHCID 5003444Sodium cyanoborohydrideHCID 12554532Methyl quinoline-7-carboxylate

Product 1

HCID 16244389Methyl 1,2,3,4-tetrahydroquinoline-7-carboxylateYield 68.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

BF3 etherate (30.5 g; 2 equiv.) was first added dropwise to a solution of methyl quinoline-7-carboxylate (20.1 g; 1 equiv.) in 200 ml of methanol. Sodium cyanoboro-hydride (13.5 g; 2 equiv.) was then added in portions. The resulting reaction mixture was stirred for 20 minutes at room temperature and heated overnight at reflux (70-80° C.). When the conversion was complete, the reaction mixture was cooled to room temperature, the solvent was removed under reduced pressure and the residue was taken up in 300 ml of water and extracted 3× with EtOAc. The combined organic phases were dried over sodium sulfate and concentrated under reduced pressure, and the crude product was recrystallised from isopropanol. Methyl 1,2,3,4-tetrahydro-quinoline-7-carboxylate (14 g; 67.3%) was obtained in the form of a colorless solid.

Workup

  1. customThe resulting reaction mixture
  2. temperatureheated overnight
  3. temperatureat reflux (70-80° C.)
  4. temperaturethe reaction mixture was cooled to room temperature
  5. customthe solvent was removed under reduced pressure
  6. extractionextracted 3× with EtOAc
  7. dry with materialThe combined organic phases were dried over sodium sulfate
  8. concentrationconcentrated under reduced pressure
  9. customthe crude product was recrystallised from isopropanol

Sources & evidence

ORD record
ord-8a1e6311e6c6412f994853f53c147747
Source dataset
uspto-grants-2013_01
Patent number
US08357717B2

Reaction notes

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