From Novasep in Germany and Organic Process Research and Development comes word that Togni’s reagent II, used for trifluoromethylations, is explosive. Also highly hazardous is an intermediate in the reagent’s synthesis and probably Togni’s reagent I.
- Work with the compounds behind a safety shield and use small amounts
- Avoid open flames and sparking
- Don’t grind the materials with “brute force” (I think I’d probably err on the side of not grinding at all)
- Use “soft and polished tools” for manipulations
- Avoid caking and disperse lumps early
- Impurities may influence the thermal and mechanical sensitivity of the material
The Sigma-Aldrich material safety data sheet for Togni’s reagent II, 1-(trifluoromethyl-1,2-benziodoxol-3(1H)-one, mixed with diatomaceous earth classifies the product only as an irritant and toxic. Togni’s reagent I, 3,3-dimethyl-1-trifluoromethyl-1,2-benziodoxole, is flagged as an irritant.