Synthesis and Crystal Structure of 4-Trifluoroacetyl-3-phenylsydnone

4-Trifluoroacetyl-3-phenylsydnone was first synthesized by trifluoromethylation of 4-formyl-3-phenylsydnone followed by oxidation of the corresponding trifluoromethyl alcohol.The structure of the product was determined by single-crystal X-ray analysis.Mesoionic compounds are five-membered heterocycles with a sextet of electrons and can be represented as hybrids of a number of mesoionic/ionic forms (polar structures). 1 Amongst the many possible members of this family of compounds, 1,3-oxazolium-5-olates (münchnones, 1), 1,3-thiazolium-5-olates (thiomünchnones, 2) and 1,2,3-oxadiazolium-5-olates (sydnones, 3) have long attracted significant attention from a wide variety of research areas due to its interesting structure and physicochemical properties (Figure 1).