Development of a Purely Isolable (Dimorpholino)triazine-Based Reagent for the Epoxidation of Alkenes

A triazine-based reagent, 2-hydroperoxy-4,6-dimorpholino-1,3,5-triazine (Triazox-II), was developed for alkene epoxidation. This reagent can be prepared from inexpensive starting materials (cyanuric chloride and morpholine) on a 15 mmol scale in two steps with 54% overall yield and isolated as a pure, bench-stable solid with low sensitivity to impact and friction. Triazox-II exhibited higher solubility in chlorinated solvents than the previously reported reagent Triazox. Epoxidation using Triazox-II was conducted in various solvents, with a preference for CH₂Cl₂ at 0.5 M concentration, resulting in epoxides in 83–94% yield. The reaction was conducted under mild conditions owing to the low acidity of the reaction coproduct.