Tributylvinyltin → 6-Ethenylpyrido[2,3-b]pyrazine

HRID 556427Notes

Reaction equation

HRID 556427 reaction equation
Cl[C:2]1[CH:3]=[CH:4][C:5]2[C:6]([N:11]=1)=[N:7][CH:8]=[CH:9][N:10]=2.[CH:12]([Sn](CCCC)(CCCC)CCCC)=[CH2:13]>C1COCC1>[CH:12]([C:2]1[CH:3]=[CH:4][C:5]2[C:6]([N:11]=1)=[N:7][CH:8]=[CH:9][N:10]=2)=[CH2:13]

Participants

4

Reactant 2

HCID 81998TributylvinyltinHCID 6408346-Chloropyrido[2,3-b]pyrazine2×

Product 1

HCID 574168446-Ethenylpyrido[2,3-b]pyrazineYield 81%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
65 °C

Procedure

6-chloropyrido[2,3-b]pyrazine (Intermediate 4.2) (3 g, 18.12 mmol, 1.00 eq.) was dissolved in THF (150 mL) and degassed with nitrogen at rt for 10 minutes. Tetrakis (triphenylphosphine)palladium(0) (1.46 g, 1.27 mmol, 0.07 eq.) and vinyltributylstannane (7.47 mL, 23.5 mmol, 1.3 eq.) were added and reaction mixture was stirred at 65° C. for 3 hours. THF was evaporated and crude purified directly by flash chromatography using cyclohexane/ethyl acetate (8/2) to give 2.3 g of the expected compound (Intermediate 4.3) as an orange oil. Amount: 2.3 g; Yield: 81%; Formula: C9H7N3; HPLC Purity: 98%; HPLC (H2O TFA 0.1%-ACN TFA 0.05%): Rt (min); Area %=1.32 min; 98%; 1H NMR (DMSO-d6) δ 9.10 (s, 1H), 8.98 (s, 1H), 8.46 (d, 1H, J=8 Hz), 7.95 (d, 1H, J=8 Hz), 6.90 (dd, 1H, Jtrans=17 Hz, Jcis=10 Hz), 6.50 (dd, 1H, Jtrans=17 Hz, Jgem=1.5 Hz), 5.80 (dd, 1H, Jcis=10 Hz, Jgem=1.5 Hz). LC-MS: M/Z ESI: Rt (min) 0.78 min, 158.13 (M+1).

Workup

  1. customdegassed with nitrogen at rt for 10 minutes
  2. customreaction mixture
  3. customTHF was evaporated
  4. customcrude purified directly by flash chromatography

Sources & evidence

ORD record
ord-ae590aff65e94d6085df8bf5a465e61b
Source dataset
uspto-grants-2011_11
Patent number
US08058289B2

Reaction notes

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