The first crystal structure of the pyrrolo[1,2-c]oxa-zole ring system

The title compound, C7H4F3NO2, 3-trifluoromethyl-1H-pyrrolo[1,2-c]oxazol-1one, is the first crystal structure of the pyrrolo[1,2-c]oxazole ring system: the fused ring system is almost planar (r.m.s. deviation = 0.006 angstrom). In the crystal, weak C-H center dot center dot center dot O and C-H center dot center dot center dot F hydrogen bonds link the molecules into [001] chains and pi-pi stacking interactions consolidate the structure.