Ethyl formate → Racemic Ethyl 6,7-Dimethoxy-3-hydroxymethylene-2-methyl-4-oxo-1,2,3,4-tetrahydroquinoline-1-carboxylate

HRID 597198Notes

Reaction equation

HRID 597198 reaction equation
[O-:1][CH2:2]C.[Na+].[H-].[Na+].[CH3:7][O:8][C:9]1[CH:10]=[C:11]2[C:16](=[CH:17][C:18]=1[O:19][CH3:20])[N:15]([C:21]([O:23][CH2:24][CH3:25])=[O:22])[CH:14]([CH3:26])[CH2:13][C:12]2=[O:27].C(OCC)=O>C1C=CC=CC=1.C(O)C>[CH3:7][O:8][C:9]1[CH:10]=[C:11]2[C:16](=[CH:17][C:18]=1[O:19][CH3:20])[N:15]([C:21]([O:23][CH2:24][CH3:25])=[O:22])[CH:14]([CH3:26])[C:13](=[CH:2][OH:1])[C:12]2=[O:27]

Participants

7

Reactant 4

HCID 8025Ethyl formateHCID 24758Sodium hydrideHCID 2723922Sodium ethoxideHCID 15480676ethyl 6,7-dimethoxy-2-methyl-4-oxo-3,4-dihydro-1(2H)-quinolinecarboxylate

Product 1

HCID 70638946Racemic Ethyl 6,7-Dimethoxy-3-hydroxymethylene-2-methyl-4-oxo-1,2,3,4-tetrahydroquinoline-1-carboxylateYield 96%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 702EthanolSolvent

Procedure

To sodium ethoxide, freshly prepared from 4.8 g. of sodium hydride and 6.0 ml. of ethanol was added a solution of 14.7 g. of ethyl 6,7-dimethoxy-2-methyl-4-oxo-1,2,3,4-tetrahydroquinoline-1-carboxylate and 19.8 ml. of ethyl formate in 150 ml. of benzene, over a 45 min. period. The reaction mixture was stirred at room temperature for 3 hrs. and then it was poured onto 250 ml. of ice water. The layers were separated, and the organic layer was extracted with 1N sodium hydroxide solution. The combined aqueous phases were washed with benzene, and then they were added dropwise to 250 ml. of 12N hydrochloric acid. This caused the product to separate in the form of an oil. Recrystallization of this oil from hexane produced 15.4 g. (96% yield) of the title compound, m.p. 98°-101° C. Further recrystallization from hexane raised the melting point to 129°-130° C.

Workup

  1. additionand then it was poured onto 250 ml
  2. customThe layers were separated
  3. extractionthe organic layer was extracted with 1N sodium hydroxide solution
  4. washThe combined aqueous phases were washed with benzene
  5. additionthey were added dropwise to 250 ml
  6. customto separate in the form of an oil
  7. customRecrystallization of this oil from hexane
  8. customproduced 15.4 g

Sources & evidence

ORD record
ord-14c804e5e53a421a9bade78cbb7dd5c2
Source dataset
uspto-grants-1977_03
Patent number
US04013662

Reaction notes

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