Aluminium lithium hydride → 1,6-Dimethyl-1,2,3,4-tetrahydropyrido[2,3-b]pyrazine

HRID 1241440Notes

Reaction equation

HRID 1241440 reaction equation
[H-].[H-].[H-].[H-].[Li+].[Al+3].[CH3:7][N:8]1[CH2:13][C:12](=O)[NH:11][C:10]2[N:15]=[C:16]([CH3:19])[CH:17]=[CH:18][C:9]1=2>C1COCC1>[CH3:7][N:8]1[CH2:13][CH2:12][NH:11][C:10]2[N:15]=[C:16]([CH3:19])[CH:17]=[CH:18][C:9]1=2

Participants

4

Reactant 2

HCID 21226445Aluminium lithium hydrideHCID 219345241,6-Dimethyl-1,4-dihydropyrido[2,3-b]pyrazin-3(2H)-one

Product 1

HCID 219345911,6-Dimethyl-1,2,3,4-tetrahydropyrido[2,3-b]pyrazineYield 91%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

LiAlH4 (214 mg, 5.64 mmol) was slowly added to 10 mL anhydrous THF in a round-bottom flask fitted with a stir bar and a condenser. After stirring for 10 minutes, a solution of 1,6-dimethyl-1,4-dihydropyrido[2,3-b]pyrazin-3(2H)-one (500 mg, 2.82 mmol) in 5 mL anhydrous THF was added drop wise. Upon completion of the addition, the reaction mixture was refluxed for 16 hours. The reaction was cooled to room temperature and quenched with 1 M NaOH solution until the mixture had become a milky yellow color. The precipitate was filtered off and washed 3 times with CH2Cl2. The filtrate and washings were combined, washed with brine, dried over MgSO4. Filtered and concentrated under reduced pressure to give the desired product as light yellow oil, which solidified on standing. (420 mg, 91% yield). H NMR (CDCl3) δ 2.27 (s, 3H), 2.80 (s, 3H), 3.17 (t, 2H), 3.58 (m, 2H), 6.36 (d, 1H), 6.56 (d, 2H).

Workup

  1. customfitted with a stir bar and a condenser
  2. additionUpon completion of the addition
  3. temperaturethe reaction mixture was refluxed for 16 hours
  4. customquenched with 1 M NaOH solution until the mixture
  5. filtrationThe precipitate was filtered off
  6. washwashed 3 times with CH2Cl2
  7. washwashed with brine
  8. dry with materialdried over MgSO4
  9. filtrationFiltered
  10. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-f1876f763bfa411882ade8d491415a8b
Source dataset
uspto-grants-2006_10
Patent number
US07115596B2

Reaction notes

Loading…