Cyanogen Bromide → 2,4,6-Trimethylphenyl(imino)imidazolidine

Participants

Reaction Steps

A solution of cyanogen bromide (1.8 g, 18.5 mmol) in anhydrous ethanol (3 mL) was added at 0° C. to a solution of N1-(2,4,6-trimethyl-phenyl)-ethane-1,2-diamine (3.0 g, 16.9 mmol) in anhydrous ethanol (9 mL) under nitrogen. The reaction mixture was warmed up to room temperature for 10 min, then was heated at 155° C. for 40 min with a flow of nitrogen to remove ethanol. Upon cooling to r.t., the resulting solids were transferred to a separatory funnel via dichloromethane (70 mL), and washed sequentially with 1 N sodium hydroxide (2×35 mL), water and brine. The organic layer was dried over anhydrous sodium sulfate and solvents were removed in vacuo to afford the title compound as a pale white solid (3.08 g, 90% yield). The solids were used for the next step without further purification. 1H NMR (CDCl3, 300 MHz) δ 6.70 (s, 2H), 3.46 (s, 4H), 2.06 (s, 3H), 1.99 (s, 6H); 13C NMR (CDCl3, 75 MHz) δ 160.1, 138.2, 137.8, 132.2, 129.5, 48.8, 43.5, 20.8, 17.5. LC/MS: tR=0.99 min., (MH+)=204.12.

Provenance & Evidence