Allyl bromide → Methyl 8-chloro-3-(prop-2-en-1-yl)imidazo[1,2-a]pyrazine-2-carboxylate

HRID 513214Notes

Reaction equation

HRID 513214 reaction equation
Br[C:2]1[N:6]2[CH:7]=[CH:8][N:9]=[C:10]([Cl:11])[C:5]2=[N:4][C:3]=1[C:12]([O:14][CH3:15])=[O:13].[CH:16]([Mg]Cl)([CH3:18])[CH3:17].[Cu](C#N)C#N.C(Br)C=C>C1COCC1.[Cl-].[Na+].O>[Cl:11][C:10]1[C:5]2[N:6]([C:2]([CH2:18][CH:16]=[CH2:17])=[C:3]([C:12]([O:14][CH3:15])=[O:13])[N:4]=2)[CH:7]=[CH:8][N:9]=1

Participants

7

Reactant 4

HCID 7841Allyl bromideHCID 71743174Methyl 3-bromo-8-chloroimidazo[1,2-A]pyrazine-2-carboxylateHCID 178418260HCID 178418260, compoundHCID 178418918HCID 178418918, compound

Product 1

HCID 86720581Methyl 8-chloro-3-(prop-2-en-1-yl)imidazo[1,2-a]pyrazine-2-carboxylateYield 22.2%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

To a suspension of methyl 3-bromo-8-chloroimidazo[1,2-a]pyrazine-2-carboxylate (250 mg, 0.861 mmol) in THF (8.6 mL) cooled to −40 C was added isopropylmagnesium chloride (0.99 mL, 1.29 mmol) dropwise. After 1 h stirring, copper cyanide (7.7 mg, 0.09 mmol) and allyl bromide (0.15 mL, 1.7 mmol) were added and the mixture was warmed to r.t. After 1 h, the reaction was poured into brine. The organic layer was separated, dried over MgSO4, filtered, and concentrated in vacuo. The crude material was purified on silica (gradient elution, 0-80% EtOAc/hexanes) to yield the title product (48 mg). HRMS (ESI) calc (M+H)+=252.0534. found 252.0539.

Workup

  1. temperaturecooled to −40 C
  2. waitAfter 1 h
  3. customThe organic layer was separated
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe crude material was purified on silica (gradient elution, 0-80% EtOAc/hexanes)

Sources & evidence

ORD record
ord-8f731757db63479da29f07e2b950c593
Source dataset
uspto-grants-2015_08
Patent number
US09102673B2

Reaction notes

Loading…