Sodium Hydroxide → ethyl 6,7-dimethoxy-2-methyl-4-oxo-3,4-dihydro-1(2H)-quinolinecarboxylate

HRID 597200Notes

Reaction equation

HRID 597200 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:12]=1[O:13][CH3:14])[N:9]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH:8]([CH3:20])[C:7](=CN)[C:6]2=[O:23].[OH-].[Na+]>C(O)C>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:12]=1[O:13][CH3:14])[N:9]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH:8]([CH3:20])[CH2:7][C:6]2=[O:23]

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 53673004l-Ethyl 6,7-dimethoxy-3-aminomethylene-2-methyl-4-oxo-1,2,3,4-tetrahydroquinoline-1-carboxylate

Product 1

HCID 15480676ethyl 6,7-dimethoxy-2-methyl-4-oxo-3,4-dihydro-1(2H)-quinolinecarboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 570 mg. of l-ethyl 6,7-dimethoxy-3-aminomethylene-2-methyl-4-oxo-1,2,3,4-tetrahydroquinoline-1-carboxylate, 1.78 ml. of 1N sodium hydroxide and 3 ml. of ethanol was heated under reflux for 24 hours and then stored at 25° C. for 3 days. The solvent was removed by evaporation in vacuo, and the residue was dissolved in ethyl acetate. The ethyl acetate solution was washed with water and then it was concentrated to give 540 mg. of an oil. The oil was chromatographed using 30 g. of silica gel, and using 6:4 benzene-ethyl acetate as solvent, giving 6 fractions. Fractions 1 and 2 were combined and recrystallized from ethyl acetate-hexane to give 49 mg. of the title product, m.p. 92°-93° C. Fractions 3-6 were combined to give 152 mg. of 6,7-dimethoxy-2-methyl-4-oxo-1,2,3,4-tetrahydroquinoline. This latter material was dissolved in 3 ml. of methylene chloride, and 3 ml. of pyridine followed by 0.5 ml. of ethyl chloroformate was added. After 20 minutes, the reaction mixture was diluted with an excess of methylene chloride and water. The organic phase was separated and washed successively with dilute hydrochloric acid, saturated sodium bicarbonate and brine. The methylene chloride solution was then dried, and evaporated in vacuo to give an oil. The oil was recrystallized from ethyl acetate-hexane to give 95 mg. of the title compound, m.p. 92°-93° C.

Workup

  1. additionA mixture of 570 mg
  2. temperatureunder reflux for 24 hours
  3. customThe solvent was removed by evaporation in vacuo
  4. dissolutionthe residue was dissolved in ethyl acetate
  5. washThe ethyl acetate solution was washed with water
  6. concentrationit was concentrated
  7. customto give 540 mg
  8. customThe oil was chromatographed
  9. customgiving 6 fractions
  10. customrecrystallized from ethyl acetate-hexane
  11. customto give 49 mg

Sources & evidence

ORD record
ord-6cca5d34b2544b6086e1f512773f6e5c
Source dataset
uspto-grants-1977_03
Patent number
US04013662

Reaction notes

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