N-(3-Cyanophenyl)-N'-(4-cyanophenyl)urea (0.25 g, 0.95 mmol) was dissolved in DMF (2 ml) and added to a cooled slurry of sodium hydride (0.80 g, 2.0 mmol, hexane washed to remove the mineral oil) in dimethylformamide (25 ml) under a nitrogen atmosphere. After strirring for 15 min, 1,4-dibromobutane (0.25 g, 0.95 mmol) was added slowly. The reaction was stirred at 0° C. for 1 h and then allowed to warm to 75° C. for 3 h. To the reaction additional sodium hydride was added and the reaction was heated to 75° C. for an additional 6 h. The reaction was allowed to cool to ambient temperature, was poured into 1N HCl and extracted with ethyl acetate. The organic layer was washed with water and brine, then dried (MgSO4) and concentrated to give a viscous oil. The oil was purified by flash chromatography on silica gel eluting with methylene chloride: ethyl acetate 95:5 to give N-(3-cyanophenyl)-N'-(4-cyanophenyl)cycloheptylurea as an oil (0.075 gm 0.24 mmol); LRMS (M+H)+ m/z 317; 1H NMR (CDCl3): 7.7-7.45(m, 6H), 7.4(d, 2H), 3.82(m, 4H), 1.95(m, 4H).
