Hydrochloric Acid → 6-(4-Benzylphenyl)-7-cyclohexyl-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid

HRID 270942Notes

Reaction equation

HRID 270942 reaction equation
C([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]2[C:14]([CH:15]3[CH2:20][CH2:19][CH2:18][CH2:17][CH2:16]3)=[C:13]([C:21]3[CH:26]=[CH:25][C:24]([CH2:27][C:28]4[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=4)=[CH:23][CH:22]=3)[CH:12]=[N:11][C:10]=12)=[O:5])C.[Li+].[OH-].Cl>O1CCCC1>[CH2:27]([C:24]1[CH:25]=[CH:26][C:21]([C:13]2[CH:12]=[N:11][C:10]3[N:9]([N:8]=[CH:7][C:6]=3[C:4]([OH:5])=[O:3])[C:14]=2[CH:15]2[CH2:16][CH2:17][CH2:18][CH2:19][CH2:20]2)=[CH:22][CH:23]=1)[C:28]1[CH:29]=[CH:30][CH:31]=[CH:32][CH:33]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 3939Lithium HydroxideHCID 691557876-(4-Benzyl-phenyl)-7-cyclohexyl-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid ethyl ester

Product 1

HCID 159581186-(4-Benzylphenyl)-7-cyclohexyl-pyrazolo[1,5-a]pyrimidine-3-carboxylic acidYield 21%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 36 mg (0.082 mmol) of 6-(4-benzyl-phenyl)-7-cyclohexyl-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid ethyl ester in 3 mL of tetrahydrofuran was added 0.5 mL (0.5 mmol) of 1 M LiOH solution, and the resulting mixture was heated at reflux overnight. The reaction mixture was then acidified with 1 M HCl solution to pH=2, and extracted with ethyl acetate. The combined organic extracts were dried over sodium sulfate, and concentrated to give a residue which was purified via reverse-phase chromatography to afford (after lyophilization) 7 mg (21% yield) of 6-(4-benzyl-phenyl)-7-cyclohexyl-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid as a solid (90% purity, entry 444) as indicated by 1H NMR; LC-MS—calcd for C26H25N3O2 [M++H]+: 412.19, found: 412.3.

Workup

  1. temperaturethe resulting mixture was heated
  2. temperatureat reflux overnight
  3. extractionextracted with ethyl acetate
  4. dry with materialThe combined organic extracts were dried over sodium sulfate
  5. concentrationconcentrated
  6. customto give a residue which
  7. customwas purified via reverse-phase chromatography

Sources & evidence

ORD record
ord-6b2828b3cd214c40bcc540c06fd3b8d5
Source dataset
uspto-grants-2008_11
Patent number
US07449488B2

Reaction notes

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