Tetrabutylammonium Fluoride → tert-Butyl 5,6-dihydroimidazo(1,2-a)pyrazine-7(8H)-carboxylate

HRID 2213053Notes

Reaction equation

HRID 2213053 reaction equation
[F-].C([N+](CCCC)(CCCC)CCCC)CCC.ClC[CH2:21][N:22]([CH2:30][C:31]1[N:32]([CH2:36]OCC[Si](C)(C)C)[CH:33]=[CH:34][N:35]=1)[C:23](=[O:29])[O:24][C:25]([CH3:28])([CH3:27])[CH3:26]>O1CCCC1>[N:35]1[CH:34]=[CH:33][N:32]2[CH2:36][CH2:21][N:22]([C:23]([O:24][C:25]([CH3:26])([CH3:27])[CH3:28])=[O:29])[CH2:30][C:31]=12

Participants

4

Reactant 2

HCID 2724141Tetrabutylammonium Fluoride2×HCID 69559434Carbamic acid, (2-chloroethyl)[[1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-imidazol-2-yl]methyl]-, 1,1-dimethylethyl ester

Product 1

HCID 21955306tert-Butyl 5,6-dihydroimidazo(1,2-a)pyrazine-7(8H)-carboxylateYield 35%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Tetrabutylammonium fluoride (1M in tetrahydrofuran, 7.1 mL, 7.1 mmol) was added to a solution of 1,1-dimethylethyl N-(2-chloroethyl)-N-(1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-imidazole-2-ylmethyl)carbamate (Description 162, 2.52 g, 6.5 mmol) in tetrahydrofuran (50 mL) and the mixture was heated under reflux for 1.5 hours. Further tetrabutylammonium fluoride (1M in tetrahydrofuran, 7.1 mL, 7.1 mmol) was added and the mixture was heated under reflux for 20 hours. The mixture was cooled and the solvent was evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with CH2Cl2/MeOH (97:3), to give the title compound (505 mg, 35%). m/z (ES+) 224 (M+1).

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 1.5 hours
  3. temperaturethe mixture was heated
  4. temperatureunder reflux for 20 hours
  5. temperatureThe mixture was cooled
  6. customthe solvent was evaporated under reduced pressure
  7. customThe residue was purified by flash column chromatography on silica gel
  8. washeluting with CH2Cl2/MeOH (97:3)

Sources & evidence

ORD record
ord-a962892eda4945aeadf8444726730051
Source dataset
uspto-grants-2006_09
Patent number
US07105507B2

Reaction notes

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