Ethanol → 7-(Tert-butoxycarbonyl)-3-phenyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyrazine-1-carboxylic acid

HRID 2110193Notes

Reaction equation

HRID 2110193 reaction equation
[C:1]1([C:7]2[N:11]3[CH2:12][CH2:13][N:14]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:15][C:10]3=[C:9]([C:23]([O:25]C)=[O:24])[N:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[Li+].[OH-].C(O)C>C1COCC1>[C:19]([O:18][C:16]([N:14]1[CH2:13][CH2:12][N:11]2[C:7]([C:1]3[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=3)=[N:8][C:9]([C:23]([OH:25])=[O:24])=[C:10]2[CH2:15]1)=[O:17])([CH3:22])([CH3:20])[CH3:21]

Participants

5

Reactant 3

HCID 702EthanolHCID 3939Lithium HydroxideHCID 576350867-tert-butyl 1-methyl 3-phenyl-5,6-dihydroimidazo[1,5-a]pyrazine-1,7(8H)-dicarboxylate

Product 1

HCID 576351557-(Tert-butoxycarbonyl)-3-phenyl-5,6,7,8-tetrahydroimidazo[1,5-a]pyrazine-1-carboxylic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To 7-tert-butyl 1-methyl 3-phenyl-5,6-dihydroimidazo[1,5-a]pyrazine-1,7(8H)-dicarboxylate (3A) (1.6 g, 4.47 mmol) in THF (50 mL) was added aqueous LiOH (0.7 g in 18.5 mL water) and ethanol (13 mL). The resulting mixture was stirred at room temperature for 2 days. The reaction mixture was concentrated under reduced pressure, diluted with water and acidified to pH 4 with 1N aqueous HCl solution. The aqueous suspension was extracted 3 times with ethyl acetate. The combined organic extracts were washed with brine, dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give Intermediate 3B as a white solid in quantitative yield. The material was used in the next step without further purification. 1H-NMR (400 MHz, CDCl3) δ: 1.52 (s, 9H), 3.81 (m, 2H), 4.14 (m, 2H), 5.02 (s, 2H), 7.46-7.51 (m, 3H), 7.62-7.68 (m, 2H). LCMS (+ESI) m/z 344.23 [M+H]+.

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. additiondiluted with water
  3. extractionThe aqueous suspension was extracted 3 times with ethyl acetate
  4. washThe combined organic extracts were washed with brine
  5. dry with materialdried over anhydrous MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-1f37b4ab83a043fa87e9968a3b9941d5
Source dataset
uspto-grants-2009_04
Patent number
US07517874B2

Reaction notes

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