Potassium Carbonate → 1H-Pyrazole-4-carbonitrile, 5-amino-1-pentyl-

HRID 1804537Notes

Reaction equation

HRID 1804537 reaction equation
[NH2:1][C:2]1[C:6]([C:7]#[N:8])=[CH:5][NH:4][N:3]=1.[CH2:9](I)[CH2:10][CH2:11][CH2:12][CH3:13].C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C>[NH2:1][C:2]1[N:3]([CH2:9][CH2:10][CH2:11][CH2:12][CH3:13])[N:4]=[CH:5][C:6]=1[C:7]#[N:8]

Participants

5

Reactant 3

HCID 11430Potassium Carbonate2×HCID 123351-IodopentaneHCID 178510443HCID 178510443, compound

Product 1

HCID 109210821H-Pyrazole-4-carbonitrile, 5-amino-1-pentyl-

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
80 °C

Procedure

3-Amino-4-pyrazolecarbonitrile 1 (Acros, 15 g, 0.138 mol), pentyliodide (Acros, 24.45 ml, 0.187 mol) and anhydrous potassium carbonate (Fisher, 25.88 g, 0.187 mol) were suspended in 100 mL anhydrous DMF and heated at 80° C. under nitrogen overnight. HPLC analysis (Method D) showed starting material still present. An additional 9 ml (69 mmol) of pethyliodide and 9.5 g (69 mmol) K2CO3 were added to the reaction and heating continued for 5 more hours. The reaction was permitted to cool and the DMF was removed on a rotary evaporator. Water was added (100 mL) and the organics were extracted with dichloromethane (3×100 mL). The combined dichloromethane fractions were washed with water (50 mL) and brine (50 mL) and were dried (magnesium sulfate). Concentration of the organics afforded orange solid which contained both pentyl isomers and residual DMF by NMR analysis (27.65 g, greater than theoretical yield). This was carried on crude. HPLC (1 peak, 63%) elutes at 9.5 minutes (Method D). 1H NMR (400 MHz, DMSO-d6) δ 7.87 (s, 1H), 7.60 (s, 1H), 6.15 (s, 1H), 5.33 (s, 2H), 3.80 (t, J=7, 2H), 1.68 (m, 2H), 1.25 (m, 4H) 0.75 (t, J=7, 3H).

Workup

  1. temperatureheating
  2. temperatureto cool
  3. customthe DMF was removed on a rotary evaporator
  4. additionWater was added (100 mL)
  5. extractionthe organics were extracted with dichloromethane (3×100 mL)
  6. washThe combined dichloromethane fractions were washed with water (50 mL) and brine (50 mL)
  7. dry with materialwere dried (magnesium sulfate)
  8. customby NMR analysis (27.65 g, greater than theoretical yield)

Sources & evidence

ORD record
ord-0e9130e9d2c345e587929d312202ca0a
Source dataset
uspto-grants-2013_01
Patent number
US08354414B2

Reaction notes

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