N -ALKOXY- N -CHLOROUREAS IN THE SYNTHESIS OF 3,4-DIHYDRO-1 H -2,1-BENZOXAZINE-1-CARBOXAMIDE AND 1-ALKOXY-1,3-DIHYDROBENZIMIDAZOL-2-ONES
The cyclization of N- chloro- N -(2-phenylethoxy)urea in the presence of silver trifluoroacetate leads to the formation of 3,4-dihydro-1 H -2,1-benzoxazine-1-carboxamide, while N -alkoxy- N' -aryl- N -chloro-ureas in the presence of sodium acetate form 1-alkoxy-1,3-dihydrobenzimidazol-2-ones. The structures of 3,4-dihydro-1 H -2,1-benzoxazine-1-carboxamide and 1-methoxy-6-nitro-1,3-dihydrobenzimidazol-2 one were examined by X-ray structural analysis. Authors: V. G. Shtamburg, O. V. Shishkin, V. V. Shtamburg, R. I. Zubatyuk, A. V. Mazepa, and R. G. Kostyanovsky. English Translation in Chemistry of Heterocyclic Compounds , 2013, 49 (8), pp 1195-1206 http://link.springer.com/article/10.1007/s10593-013-1363-5