Reactions with 1-Benzotriazolecarboxylic Acid Chloride. VIII. Synthesis of N-Hydroxyisocyanate Derivatives

1,3,5-Trihydroxy-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (5), the tri-mer of hypothetical acid HO–N=C=O, was synthesized by hydro-genolysis of 1,3,5-tribenzyloxy-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (4). Similarly, the 1-(N-hydroxycarbamoyl)benzotriazole (6), as »solid HONCO donor«, was prepared by hydrogenolysis of its benzyl de-rivatives 2. Compound 4 was obtained by trimerization of interme-diary N-benzyloxyisocyanate (3), which liberates in the thermal dis-sociation of 1-(N-benzyloxycarbamoyl)benzotriazole (2). In the reac-tion with 2-phenylethylamine, compound 6 gave N-hydroxy-N-(2-phenylethyl)urea (7)