Hydrochloric Acid → Ethyl 7-aminoquinoline-3-carboxylate

HRID 2228933Notes

Reaction equation

HRID 2228933 reaction equation
Cl.[CH2:2]([O:4][C:5]([C:7]1[CH:8]=[N:9][C:10]2[C:15]([CH:16]=1)=[CH:14][CH:13]=[C:12]([N:17]=C(C1C=CC=CC=1)C1C=CC=CC=1)[CH:11]=2)=[O:6])[CH3:3]>C(O)C>[CH2:2]([O:4][C:5]([C:7]1[CH:8]=[N:9][C:10]2[C:15]([CH:16]=1)=[CH:14][CH:13]=[C:12]([NH2:17])[CH:11]=2)=[O:6])[CH3:3]

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 102872307-(Benzhydrylidene-amino)-quinoline-3-carboxylic acid ethyl ester

Product 1

HCID 9877801Ethyl 7-aminoquinoline-3-carboxylateYield 68.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Concentrated hydrochloric acid (1 mL, 2.5 volumes) was added to a solution of 7-(benzhydrylidene-amino)-quinoline-3-carboxylic acid ethyl ester (400 mg, 1.05 mmol, 1 equiv) in ethanol (4 mL, 10 volumes). The solution was stirred at room temperature for three hours and then concentrated. The residue was dissolved in ethyl acetate (20 mL, 50 volumes) and the organic layer was washed with 1 N hydrochloric acid (5×25 mL). The pH of the combined aqueous layer was then adjusted to about 8 with solid sodium hydroxide. The aqueous layer was then extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over sodium sulfate and concentrated to provide 7-amino-quinoline-3-carboxylic acid ethyl ester (155 mg, 68%) as a yellow solid. The crude solid can be further purified by flash column chromatography using silica gel (EM Science, Gibbstown, N.J., 230-400 mesh) in 60% ethyl acetate in hexanes if desired.

Workup

  1. concentrationconcentrated
  2. dissolutionThe residue was dissolved in ethyl acetate (20 mL, 50 volumes)
  3. washthe organic layer was washed with 1 N hydrochloric acid (5×25 mL)
  4. extractionThe aqueous layer was then extracted with ethyl acetate (3×50 mL)
  5. dry with materialThe combined organic layers were dried over sodium sulfate
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-f468ab9e614443f8b551d7a6fef60240
Source dataset
uspto-grants-2002_07
Patent number
US06417367B1

Reaction notes

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