Abstract
Nitrosation of 1-methyl-(Ia), 1-(2-chloroethyl)-(Ib) and 1-phenyl-3-(2-pyridylmethyl)-urea (Id) with hydrochloric acid and sodium nitrite gave exclusively the corresponding 1-nitrosoureas (IIa, b, d). However, nitrosation of the 1-isopropylurea (Ic) gave a mixture of the 1-nitrosourea (IIc) and the 3-nitrosourea (IIIc). Similar results were also obtained in the nitrosation of 1-substituted 3-(2-pyridylethyl) ureas (Ie-h). The reaction of the nitrosoureas and m-chloroperbenzoic acid in chloroform gave the N-oxides (IVa-f, Vc, f, g), which were more stable than the nitrosoureas.
