Water → 4-Hydroxyimino-6,7-dimethoxy-2-methyl-3,4-dihydro-2H-quinoline-1-carboxylic acid ethyl ester

HRID 370033Notes

Reaction equation

HRID 370033 reaction equation
[CH2:1]([O:3][C:4]([N:6]1[C:15]2[C:10](=[CH:11][C:12]([O:18][CH3:19])=[C:13]([O:16][CH3:17])[CH:14]=2)[C:9](=O)[CH2:8][CH:7]1[CH3:21])=[O:5])[CH3:2].Cl.[NH2:23][OH:24].C([O-])(=O)C.[Na+].O>C(O)C>[CH2:1]([O:3][C:4]([N:6]1[C:15]2[C:10](=[CH:11][C:12]([O:18][CH3:19])=[C:13]([O:16][CH3:17])[CH:14]=2)[C:9](=[N:23][OH:24])[CH2:8][CH:7]1[CH3:21])=[O:5])[CH3:2]

Participants

6

Reactant 4

HCID 962WaterHCID 443297Hydroxyamine hydrochlorideHCID 517045Sodium AcetateHCID 15480676ethyl 6,7-dimethoxy-2-methyl-4-oxo-3,4-dihydro-1(2H)-quinolinecarboxylate

Product 1

HCID 867559824-Hydroxyimino-6,7-dimethoxy-2-methyl-3,4-dihydro-2H-quinoline-1-carboxylic acid ethyl esterYield 116.8%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A stirred solution of 6,7-dimethoxy-2-methyl-4-oxo-3,4-dihydro-2H-quinoline-1-carboxylic acid ethyl ester (10.0 g, 34.1 mmol), hydroxylamine hydrochloride (7.1 g, 102 mmol), and sodium acetate (7.0 g, 85 mmol) in ethanol (50 mL) was heated at reflux for 2 h. Water (50 mL) was added, and the volatiles were removed in vacuo. Ethyl acetate (175 mL) was added, and the mixture was stirred vigorously for 10 min. The aqueous phase was separated and extracted with ethyl acetate (2×60 mL). The combined organic layers were washed with brine (25 mL), dried over magnesium sulfate, filtered and concentrated in vacuo to give the title compound as a white foam (12.28 g, ca. 100%). 1H NMR (CDCl3) δ 1.1 (d, 3H), 1.32 (t, 3H), 2.77 (dd, 1H), 3.07 (dd, 1H), 3.89 (s, 6H), 4.2-4.4 (m, 2H), 5.0 (m, 1H), 7.18 (s, 1H), 7.26 (s, 1H).

Workup

  1. temperatureat reflux for 2 h
  2. customthe volatiles were removed in vacuo
  3. additionEthyl acetate (175 mL) was added
  4. customThe aqueous phase was separated
  5. extractionextracted with ethyl acetate (2×60 mL)
  6. washThe combined organic layers were washed with brine (25 mL)
  7. dry with materialdried over magnesium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-1d7fa16d80f24dbbbb8412ba88eaef99
Source dataset
uspto-grants-2000_10
Patent number
US06140342

Reaction notes

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