Ethyl Acetate → 5-tosyl-5H-pyrrolo[2,3-b]pyrazine-2-carbaldehyde

HRID 1854391Notes

Reaction equation

HRID 1854391 reaction equation
[CH:1](/[C:9]1[N:10]=[C:11]2[CH:17]=[CH:16][N:15]([S:18]([C:21]3[CH:27]=[CH:26][C:24]([CH3:25])=[CH:23][CH:22]=3)(=[O:20])=[O:19])[C:12]2=[N:13][CH:14]=1)=C\C1C=CC=CC=1.I([O-])(=O)(=O)=[O:29].[Na+].[O-]S([O-])(=S)=O.[Na+].[Na+].CCOC(C)=O>O1CCOCC1.O.[Os](=O)(=O)(=O)=O>[S:18]([N:15]1[C:12]2=[N:13][CH:14]=[C:9]([CH:1]=[O:29])[N:10]=[C:11]2[CH:17]=[CH:16]1)([C:21]1[CH:27]=[CH:26][C:24]([CH3:25])=[CH:23][CH:22]=1)(=[O:20])=[O:19]

Participants

8

Reactant 4

HCID 8857Ethyl AcetateHCID 24477Sodium ThiosulfateHCID 23667635Sodium periodate2×HCID 58009875HCID 58009875, compound

Product 1

HCID 580098835-tosyl-5H-pyrrolo[2,3-b]pyrazine-2-carbaldehydeYield 80%

Reagents, catalysts & solvents 3

HCID 30318Osmium TetroxideCatalyst2×HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

To a solution of (E)-2-styryl-5-tosyl-5H-pyrrolo[2,3-b]pyrazine (1.2 g, 3.2 mmol) in 1,4-dioxane (20 mL) and water (2.0 mL) was added sodium periodate (2.73 g, 12.8 mmol) followed by osmium tetroxide (2.5% in t-BuOH, 4.01 mL, 0.320 mmol). After about 1 day at ambient temperature, additional sodium periodate (2.73 g, 12.78 mmol) and osmium tetroxide (2.5% in t-BuOH, 4.01 mL, 0.320 mmol) were added. After about 2 days, a solution of aqueous Na2S2O3 (100 mL) and EtOAc (100 mL) was added. The organic layer was separated, dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The resulting solid was triturated with heptane to remove benzaldehyde. The resulting solid was dried in vacuo to provide 5-tosyl-5H-pyrrolo[2,3-b]pyrazine-2-carbaldehyde as a brown solid (0.77 g, 80%): LC/MS (Table 2, Method a) Rt=2.01 min; MS m/z: 334 (M+H)+.

Workup

  1. waitAfter about 2 days
  2. customThe organic layer was separated
  3. dry with materialdried over anhydrous Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated under reduced pressure
  6. customThe resulting solid was triturated with heptane
  7. customto remove benzaldehyde
  8. customThe resulting solid was dried in vacuo

Sources & evidence

ORD record
ord-ecd9fad5ab3a43a0a8106196d6713179
Source dataset
uspto-grants-2015_02
Patent number
US08962629B2

Reaction notes

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