Diazo-Transfer Reagent 2-Azido-4,6-dimethoxy-1,3,5-triazine Displays Highly Exothermic Decomposition Comparable to Tosyl Azide.

2-Azido-4,6-dimethoxy-1,3,5-triazine (ADT) was reported recently as a new "intrinsically safe" diazo-transfer reagent. This assessment was based on differential scanning calorimetry data indicating that ADT exhibits endothermic decomposition. We present DSC data on ADT that show exothermic decomposition with an initiation temperature ( Tinit) of 159 °C and an enthalpy of decomposition (Δ HD) of -1135 J g-1 (-207 kJ mol-1). We conclude that ADT is potentially explosive and must be treated with caution, being of comparable exothermic magnitude to tosyl azide (TsN3). A maximum recommended process temperature for ADT is 55 °C.