5-Methoxy-2-methylquinoline → (S)-5-methoxy-2-methyl-1,2,3,4-tetrahydroquinoline

HRID 1051551Notes

Reaction equation

HRID 1051551 reaction equation
[CH3:1][O:2][C:3]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:4]=1[CH:5]=[CH:6][C:7]([CH3:13])=[N:8]2.[H][H]>CO>[CH3:1][O:2][C:3]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:4]=1[CH2:5][CH2:6][C@H:7]([CH3:13])[NH:8]2

Participants

4

Reactant 2

HCID 113327475-Methoxy-2-methylquinolineHCID 178418361HCID 178418361, compound3×

Product 1

HCID 118075405(S)-5-methoxy-2-methyl-1,2,3,4-tetrahydroquinolineYield 98%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A 30-mL glass-lined stainless steel reactor with a magnetic stirring bar was charged with 5-methoxy-2-methylquinoline (4.0 g, 23.1 mmol), Ru(OTf)(η6-hexamethylbenzene)((S,S)-TsDPEN)([N-[(1S,2S)-2-(amino-κN)-1,2-diphenylethyl]-4-methylbenzenesulfonamidato-κN][(1,2,3,4,5,6-η)-1,2,3,4,5,6-hexamethylbenzene](1,1,1-trifluoromethanesulfonato-κO)-ruthenium, prepared according to the procedure in J. Am. Chem. Soc. 2011, 133, 9878-9891) (0.100 g, 0.13 mmol) and methanol (10 mL). The reactor was closed and hydrogen gas was initially introduced in at a pressure of 50 atm, before being reduced to 1 atm. After this procedure was repeated three times, the reactor was pressurized with hydrogen to 50 atm. The resulting mixture was stirred under this hydrogen pressure for 24 h at room temperature. After carefully releasing the hydrogen, the reaction mixture was concentrated under vacuum. The residue was purified via column chromatography on silica gel (gradient elution with 0-20% ethyl acetate/petroleum ether) to afford (2S)-5-methoxy-2-methyl-1,2,3,4-tetrahydroquinoline (4.0 g, 98%, >99% ee) as yellow oil. MS (ES, m/z): 178 [M+H]+

Workup

  1. customprepared
  2. customThe reactor was closed
  3. concentrationthe reaction mixture was concentrated under vacuum
  4. customThe residue was purified via column chromatography on silica gel (gradient elution with 0-20% ethyl acetate/petroleum ether)

Sources & evidence

ORD record
ord-3d627d9c13e343a78672fd30a23086f5
Source dataset
uspto-grants-2016_07
Patent number
US09388161B2

Reaction notes

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