1.2.3- Triazino triazepines

The reaction of the dithioxo compound (6) with A -aryl-C-ethoxycarbonylnitrilimines (8) led to the l,2,4-triazino-[4,3-(f]-l,2,4-triazepine (10) via the 1,3-dipolar cycloadduct (9) <92BSB977>. Treatment of 2,7-dimethyl-3,5-dimethylthio-l,2,4-triazepine (7) with mesitonitrile oxide in aqueous medium resulted in peri- and regioselective cycloaddition, giving rise to the isoxazolo[5,4-e]-1,2,4-triazepine (12) (80% yield) via the cycloadduct (11). The cycloaddition of dichlorocarbene to (7) also proceeded to form the azirino[2,l- ]-l,2,4-triazepine (13) <85RTC129>. 

---