6-Ethenylpyrido[2,3-b]pyrazine → Pyrido[2,3-b]pyrazine-6-carbaldehyde

HRID 556428Notes

Reaction equation

HRID 556428 reaction equation
[CH:1]([C:3]1[CH:4]=[CH:5][C:6]2[C:7]([N:12]=1)=[N:8][CH:9]=[CH:10][N:11]=2)=C.O=O.[O:15]=[O+][O-]>CO>[N:11]1[CH:10]=[CH:9][N:8]=[C:7]2[N:12]=[C:3]([CH:1]=[O:15])[CH:4]=[CH:5][C:6]=12

Participants

4

Reactant 2

HCID 574168446-Ethenylpyrido[2,3-b]pyrazine2×HCID 131711318Oxygen ozone

Product 1

HCID 11542824Pyrido[2,3-b]pyrazine-6-carbaldehydeYield 60%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
-70 °C

Procedure

6-vinylpyrido[2,3-b]pyrazine (Intermediate 4.3) (1 g, 6.37 mmol, 1 eq.) was dissolved in methanol (20 mL) and cooled down to −70° C. A gentle flux of a mixture of oxygen/ozone was then bubbled through for 20 minutes. The reaction was monitored by TLC using cyclohexane/ethyl acetate (8/2). When the reaction was finished, dimethylsulfide (0.1 mL) was added and reaction was left at rt for 30 minutes. Methanol was evaporated under vacuum and 600 mg of pyrido[2,3-b]pyrazine-6-carbaldehyde was recovered. Crude material was analyzed without further purification (Intermediate 4.4). Amount: 0.60 g; Yield: 60%; Formula: C8H5N3O; HPLC Purity: 90%; HPLC (H2O TFA 0.1%-ACN TFA 0.05%): Rt (min); Area %=0.90 min; 90%; 1H NMR (DMSO-d6) δ 10.1 (l, 1H), 9.05 (s, 1H), 8.95 (s, 1H), 8.70 (d, 1H, J=8 Hz), 8.20 (d, 1H, J=8 Hz); LC-MS: M/Z ESI: Rt (min) 0.76 min, 158.13 (M+1).

Workup

  1. customwas then bubbled through for 20 minutes
  2. additiondimethylsulfide (0.1 mL) was added
  3. customreaction
  4. customMethanol was evaporated under vacuum and 600 mg of pyrido[2,3-b]pyrazine-6-carbaldehyde
  5. customwas recovered
  6. customCrude material was analyzed without further purification (Intermediate 4.4)
  7. custom=0.90 min

Sources & evidence

ORD record
ord-75d4f0d09d144d9da45c7d8ac260f22d
Source dataset
uspto-grants-2011_11
Patent number
US08058289B2

Reaction notes

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