Hydrochloric Acid → 1,2,3,4-Tetrahydroquinoline-5-carboxylic acid

HRID 613644Notes

Reaction equation

HRID 613644 reaction equation
[N:1]1[C:10]2[CH:9]=[CH:8][CH:7]=[C:6]([C:11]([OH:13])=[O:12])[C:5]=2[CH:4]=[CH:3][CH:2]=1.Cl.C(=O)(O)[O-].[Na+].C(OCC)(=O)C>C(O)(=O)C>[NH:1]1[C:10]2[CH:9]=[CH:8][CH:7]=[C:6]([C:11]([OH:13])=[O:12])[C:5]=2[CH2:4][CH2:3][CH2:2]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8857Ethyl AcetateHCID 232489Quinoline-5-carboxylic acidHCID 516892Sodium Bicarbonate

Product 1

HCID 139310691,2,3,4-Tetrahydroquinoline-5-carboxylic acidYield 27.4%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
90 °C

Procedure

To a mixture of quinoline-5-carboxylic acid (4 g) in acetic acid (40 ml) was added borane-pyridine complex (8.59 g) at ambient temperature. After stirred for 18 hours, to the reaction mixture was added 1N hydrochloric acid and heated at 90° C. for 1 hour. The mixture was neutralized with aqueous sodium bicarbonate solution and ethyl acetate was added thereto. The precipitate was filtered off. The organic layer was separated, washed with water, dried over magnesium sulfate and evaporated in vacuo. The residue was purified by flash silica gel chromatography eluted with chloroform-methanol and crystallized from diisopropyl ether to give 1,2,3,4-tetrahydroquinoline-5-carboxylic acid (1.12 g) as pale brown crystals.

Workup

  1. additionwas added borane-pyridine complex (8.59 g) at ambient temperature
  2. additionwas added
  3. filtrationThe precipitate was filtered off
  4. customThe organic layer was separated
  5. washwashed with water
  6. dry with materialdried over magnesium sulfate
  7. customevaporated in vacuo
  8. customThe residue was purified by flash silica gel chromatography
  9. washeluted with chloroform-methanol
  10. customcrystallized from diisopropyl ether

Sources & evidence

ORD record
ord-b61a507114b3403a87d8ecc5e6a7b989
Source dataset
uspto-grants-1999_12
Patent number
US06008229

Reaction notes

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