Tetrahydrofuran → Rac-8-ethyl-2,3-diphenyl-5,6,7,8-tetrahydropyrido[2,3-b]pyrazine

HRID 406259Notes

Reaction equation

HRID 406259 reaction equation
Br[CH:2]1[C:11]2[C:6](=[N:7][C:8]([C:18]3[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=3)=[C:9]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)[N:10]=2)[N:5](C(OC(C)(C)C)=O)[CH2:4][CH2:3]1.[CH2:31]1COC[CH2:32]1.[Cl-].[NH4+]>C(OCC)C.[N+]([O-])([O-])=O.[Ag+]>[CH2:31]([CH:2]1[C:11]2[C:6](=[N:7][C:8]([C:18]3[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=3)=[C:9]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)[N:10]=2)[NH:5][CH2:4][CH2:3]1)[CH3:32]

Participants

6

Reactant 3

HCID 8028TetrahydrofuranHCID 25517Ammonium ChlorideHCID 66666005tert-Butyl 8-bromo-2,3-diphenyl-7,8-dihydropyrido[2,3-b]pyrazine-5(6H)-carboxylate2×

Product 1

HCID 66666341Rac-8-ethyl-2,3-diphenyl-5,6,7,8-tetrahydropyrido[2,3-b]pyrazine

Reagents, catalysts & solvents 2

HCID 24470Silver NitrateCatalystHCID 3283Diethyl EtherSolvent

Procedure

To a mixture comprising tert-butyl 8-bromo-2,3-diphenyl-7,8-dihydropyrido[2,3-b]pyrazine-5(6H)-carboxylate (Intermediate H) (200 mg, 0.429 mmol) and silver nitrate (0.728 mg, 4.29 μmol) in diethyl ether (4 ml) under nitrogen at RT was added 1-Methylmagnesium bromide in THF (0.557 ml, 0.557 mmol). The reaction mixture was left to stir at RT for 3 h under an atmosphere of nitrogen. The mixture was poured into a saturated ammonium chloride solution (10 ml) and extracted with EtOAc (2×10 ml). The organic extracts were combined, dried over MgSO4, filtered and concentrated in vacuo. The resulting crude product was purified by chromatography on silica eluting with 0-30% EtOAc/iso-hexane to afford the title compound;

Workup

  1. waitThe reaction mixture was left
  2. extractionextracted with EtOAc (2×10 ml)
  3. dry with materialdried over MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customThe resulting crude product was purified by chromatography on silica eluting with 0-30% EtOAc/iso-hexane

Sources & evidence

ORD record
ord-2fdc762b779648218d4031b5a81ddb6a
Source dataset
uspto-grants-2014_06
Patent number
US08754085B2

Reaction notes

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