Water → (R)-Octahydro-pyrido[1,2-a]pyrazine

HRID 968646

Reaction equation

HRID 968646 reaction equation
O=[C:2]1[NH:7][CH2:6][C:5](=O)[N:4]2[CH2:9][CH2:10][CH2:11][CH2:12][C@H:3]12.[H-].[Al+3].[Li+].[H-].[H-].[H-].O.[OH-].[Na+]>O1CCCC1>[CH2:2]1[NH:7][CH2:6][CH2:5][N:4]2[CH2:9][CH2:10][CH2:11][CH2:12][C@H:3]12

Participants

6

Reactant 4

HCID 962Water2×HCID 14798Sodium HydroxideHCID 21226445Aluminium lithium hydrideHCID 66936119(9aR)-octahydro-1H-pyrido(1,2-a)pyrazine-1,4-dione

Product 1

HCID 773775(R)-Octahydro-pyrido[1,2-a]pyrazineYield 69.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

(R)-Octahydro-1,4-dioxo-2H-pyrido[1,2-a]pyrazine (0.5 g, 2.98 mmol) was added portionwise to a stirred solution of lithium aluminium hydride (1M in tetrahydrofuran; 11.9 ml, 11.9 mmol). The resulting mixture was heated under reflux for 0.5 h. The solution was then cooled to 0° C. and treated dropwise with water (1.35 ml), 1 M sodium hydroxide solution (0.45 ml), then water (1.35 ml). Tetrahydrofuran (10 ml) was added and the solution stirred for 0.5 h, before filtration. The filter cake was washed with tetrahydrofuran (2×5 ml) and the combined filtrate and washings concentrated to yield (R)-octahydro-2H-pyrido[1,2-a]pyrazine as a yellow oil (0.29 g, 2.07 mmol).

Workup

  1. temperatureThe resulting mixture was heated
  2. temperatureunder reflux for 0.5 h
  3. washThe filter cake was washed with tetrahydrofuran (2×5 ml)
  4. concentrationthe combined filtrate and washings concentrated

Sources & evidence

ORD record
ord-d8177b0d07644d80a3a48c4387a17559
Source dataset
uspto-grants-2007_12
Patent number
US07304064B2

Linked notes

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