The general method of preparation of 5-nitro-3, 5-dialkyItetrahydro-l, 3-oxazines given by Senkus [1],[2] involves the direct reaction of 2-nitro-2-alkylpropane-1, 3-diol with formaldehyde and primary amines in an aqueous medium and purification of the resulting oily products by vacuum distillation. On the other hand, in the methods of synthesis of these derivatives developed by Urbanski and coworkers [3]—[6] the oxazines are separated in ...
