Dimethyl Ether → tert-butyl 4-methylene-3,4-dihydro-2H-quinoline-1-carbamate

HRID 551828Notes

Reaction equation

HRID 551828 reaction equation
[CH3:1]C(C)([O-])C.[K+].COC.O=[C:11]1[C:20]2[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=2)[N:14]([NH:21][C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH2:13][CH2:12]1>O1CCCC1.[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[CH2:1]=[C:11]1[C:20]2[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=2)[N:14]([NH:21][C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH2:13][CH2:12]1

Participants

6

Reactant 3

HCID 8254Dimethyl EtherHCID 23665647Potassium tert-butoxideHCID 67190363tert-butyl 4-oxo-3,4-dihydro-2H-quinoline-1-carbamate

Product 1

HCID 67188896tert-butyl 4-methylene-3,4-dihydro-2H-quinoline-1-carbamate

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 8028TetrahydrofuranSolvent

Procedure

3.96 ml of a 1N solution of potassium tert-butoxide in tetrahydrofuran, 1.45 g of methyltriphenylphosphonium bromide and 30 ml of dimethyl ether are placed in a 150 ml three-necked flask equipped with a magnetic stirrer and placed under an inert atmosphere. The reaction mixture is heated at reflux for 1 h. After returning to ambient temperature, 0.7 g of tert-butyl 4-oxo-3,4-dihydro-2H-quinoline-1-carbamate is added and the reaction mixture is heated at reflux for 1.5 h and then concentrated under reduced pressure. Water and ethyl acetate are added. The organic phase is washed with water, dried over magnesium sulfate and concentrated under reduced pressure. The residue is chromatographed on silica gel eluted with dichloromethane. 0.556 g of tert-butyl 4-methylene-3,4-dihydro-2H-quinoline-1-carbamate is obtained.

Workup

  1. customequipped with a magnetic stirrer
  2. temperatureThe reaction mixture is heated
  3. temperatureat reflux for 1 h
  4. customAfter returning to ambient temperature
  5. temperaturethe reaction mixture is heated
  6. temperatureat reflux for 1.5 h
  7. concentrationconcentrated under reduced pressure
  8. additionWater and ethyl acetate are added
  9. washThe organic phase is washed with water
  10. dry with materialdried over magnesium sulfate
  11. concentrationconcentrated under reduced pressure
  12. customThe residue is chromatographed on silica gel
  13. washeluted with dichloromethane

Sources & evidence

ORD record
ord-0eeaf3d00fab41198467d7ee36e3cf83
Source dataset
uspto-grants-2011_05
Patent number
US07947834B2

Reaction notes

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