Reaction #8589

Reaction equation

nitric acid

aniline

cyanamide

→

N-phenylguanidinium nitrate

Yield 32.0%

Solvents

ethanol

Conditions

Workup

1. 1
   TemperatureThe mixture was heated
2. 2
   Temperatureat reflux for 3.5 hours
3. 3
   ConcentrationThe mixture was concentrated in vacuo
4. 4
   Otherthe residue was crystallized from methanol/ethyl acetate/dichloromethane

Procedure

To a room temperature solution of aniline (10.0 g, 107 mmol) in ethanol (100 mL) was added cyanamide (9.6 mL, 50 wt% in water, 123 mmol) followed by the dropwise addition of concentrated nitric acid (7.56 mL). The mixture was heated at reflux for 3.5 hours and allowed to cool to room temperature. The mixture was concentrated in vacuo and the residue was crystallized from methanol/ethyl acetate/dichloromethane to yield N-phenylguanidinium nitrate (6.7 g, 32%) as a white crystalline solid. 1H NMR (DMSO-d6): δ 9.63 (s, 1 H), 7.44 (t, 2 H), 7.37 (broad s, 3 H), 7.29 (t, 1 H), 7.23 (d, 2 H); 13C NMR (DMSO-d6): δ 156.36, 135.99, 130.40, 127.19, 125.18; MS m/z 136 (M+1 of free base).

Source