Thermal reaction of N-(1-azido-2-oxoalkylidene)-N′-(o-alkenyloxyphenyl)hydrazines; intramolecular 1,4-cycloaddition of 1,2,4-triaza-1,3-diene intermediates
Abstract
Functionalised C-azido-hydrazones (1) were prepared by treating the corresponding chloro-hydrazones (2) with sodium azide under phase-transfer conditions. Treatment of the hydrazones (1) with boiling benzene afforded 3,4,4a,5-tetrahydro[1,2,4]triazino[6,1-c][1,4]benzoxazines (3). Mechanisms are discussed.