Glyoxal → 6-Chloropyrido[2,3-b]pyrazine

HRID 556426Notes

Reaction equation

HRID 556426 reaction equation
[Cl:1][C:2]1[N:7]=[C:6]([NH2:8])[C:5]([NH2:9])=[CH:4][CH:3]=1.[CH:10]([CH:12]=O)=O>C1COCC1>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[C:6]([N:7]=1)=[N:8][CH:10]=[CH:12][N:9]=2

Participants

4

Reactant 2

HCID 7860GlyoxalHCID 106306156-Chloropyridine-2,3-diamine2×

Product 1

HCID 6408346-Chloropyrido[2,3-b]pyrazineYield 100%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

6-chloro-2,3-pyridinediamine (Intermediate 4.1) (1 g, 6.96 mmol, 1 eq.) was dissolved in THF (15 mL). Glyoxal (0.84 mL, 18.1 mmol, 2.5 eq.) was added and reaction mixture stirred at rt for 2 hours. Reaction was monitored by RP-HPLC. THF was evaporated, residue re-dissolved in ethyl acetate (30 mL). Organic phases washed twice with saturated Na2CO3, dried with magnesium sulfate and evaporated under vacuum to give 1.15 g of the expected compound as a white solid (Intermediate 4.2). Amount: 1.15 g; Yield: 100%; Formula: C7H4N3Cl; HPLC Purity: 98%; HPLC (H2O TFA 0.1%-ACN TFA 0.05%): Rt (min); Area %=1.2 min; 98%; 1H NMR (CDCl3) δ 9.0 (s, 1H), 8.88 (s, 1H), 8.36 (d, 1H, J=8 Hz), 7.67 (d, 1H, J=8 Hz); LC-MS: M/Z ESI: Rt (min) 0.68 min, 167.0 (M+1).

Workup

  1. customreaction mixture
  2. customReaction
  3. customTHF was evaporated
  4. dissolutionresidue re-dissolved in ethyl acetate (30 mL)
  5. washOrganic phases washed twice with saturated Na2CO3
  6. dry with materialdried with magnesium sulfate
  7. customevaporated under vacuum

Sources & evidence

ORD record
ord-01a6f5b6f0a647309649bb02858e3c48
Source dataset
uspto-grants-2011_11
Patent number
US08058289B2

Reaction notes

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