Reactions of 1-Nitroso-1-phenyl-3-(4-pyridylmethyl)ureas

Treatment of 1-nitroso-1-phenyl- and 1-nitroso-1-(4-tolyl)-3-(4-pyridylmethyl)ureas (Ia, b) with methanol and ethanol at room temperature gave methyl and ethyl N-(4-pyridylmethyl)-carbamates (IIIa, b) in almost quantitative yields, together with benzene (IVa) and toluene (IVb), respectively. Treatment of Ia, b with benzene at 70°C gave 4-pyridylmethylamine (V) with biphenyl (VIa) and its 4-methyl derivative (VIb), respectively. Treatment of Ia, b with sodium azide in aqueous acetone at -5°C gave 1, 3-bis(4-pyridylmethyl)urea (VII) and phenylazides (VIIIa, b) in more than 90% yields.Compound Ia showed antitumor activity against rat ascites hepatoma AH13, but not against mouse lymphoid leukemia L1210. The mechanisms of these reactions and the mechanism of antitumor action of Ia are discussed