The Taming of Halogen Azides, Improved Syntheses and Some Reaction Chemistry of Fluorine Azide and Chlorine Azide

Scalable methods for the safe production and handling of the highly explosive FN3 and ClN3 were developed by direct fluorination of HN3 or (CH3)3SiN3 in inert fluorocarbon or SO2 solutions using elemental fluorine or ClF, respectively. As an alternate method for FN3, the metathetical preparation of thermally unstable NF4N3 which can decompose to FN3 and NF3 is proposed. The use of these methods allows the safe scale up of the FN3 pro-duction from 20 mg to a multi gram scale and to study its reaction chemistry. It was also found that HF pro-tonates HN3 to yield [H2N3]+[HF2]-, and that the reaction of FN3 in CF3CFHCF3 with HF/SbF5 solutions at-64 degrees C produces [NH2F2]+[SbF6]-. Furthermore, FN3 can be added across the C = C double bonds of CFCl=CF2 and CF2--CFCF3, and results with trans-stilbene in the formation of a triazole.