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

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence