Pentane → 3-(tert-Butyl)-1-(4-methoxyphenyl)-1H-pyrazol-5-amine

HRID 75588

Reaction equation

HRID 75588 reaction equation
[CH3:1][C:2]([CH3:9])([CH3:8])[C:3](=O)[CH2:4][C:5]#[N:6].[CH3:10][O:11][C:12]1[CH:17]=[CH:16][C:15]([NH:18][NH2:19])=[CH:14][CH:13]=1.CCCCC>C(O)C.C(O)(=O)C>[C:2]([C:3]1[CH:4]=[C:5]([NH2:6])[N:18]([C:15]2[CH:16]=[CH:17][C:12]([O:11][CH3:10])=[CH:13][CH:14]=2)[N:19]=1)([CH3:9])([CH3:8])[CH3:1]

Participants

6

Reactant 3

HCID 8003PentaneHCID 77023(4-Methoxyphenyl)hydrazineHCID 108871Pentanenitrile, 4,4-dimethyl-3-oxo-

Product 1

HCID 111393953-(tert-Butyl)-1-(4-methoxyphenyl)-1H-pyrazol-5-amineYield 82.5%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 702EthanolSolvent

Procedure

4,4-Dimethyl-3-oxo-pentanenitrile (14.28 g, 114 mmol) and 4-methoxyphenyl hydrazine (19.89 g, 114 mmol) were dissolved in a mixture of absolute ethanol (170 mL) and glacial acetic acid (5.0 mL) then heated to reflux for 3 h, before allowing to standing overnight at RT. The resulting red/brown solid was filtered off, and the filtrate was then diluted with water (500 mL), and basified with 880 ammonia solution until the pH=5. This aqueous solution was extracted into diethyl ether (3×). The combined organics were dried (MgSO4) and evaporated in vacuo to a brown oil. Trituration (pentane) gave the title compound as a light purple/brown solid (23.07 g, 94.1 mmol, 82%). LCMS (method 1): Rt 2.87 min, m/z 246/247 [MH+].

Workup

  1. temperaturethen heated
  2. temperatureto reflux for 3 h
  3. filtrationThe resulting red/brown solid was filtered off
  4. additionthe filtrate was then diluted with water (500 mL)
  5. extractionThis aqueous solution was extracted into diethyl ether (3×)
  6. dry with materialThe combined organics were dried (MgSO4)
  7. customevaporated in vacuo to a brown oil

Sources & evidence

ORD record
ord-9677a2f941934c0ca1ef9a121bd37711
Source dataset
uspto-grants-2014_09
Patent number
US08835431B2

Linked notes

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