3-(9H-Carbazol-9-yl)-2H-chromen-2-one

The title compound, C21H13NO2, was prepared as an example of a new synthesis of carbazoles from a cyclic dibenzoiodolium salt via a twofold Pd-catalysed arylation of a primary amine. The two essentially planar pi-subsystems [maximum deviations from the mean square plane of 0.038 (2) angstrom in the carbazole and 0.059 (2) angstrom in the coumarine unit] open a dihedral angle of 63.05 (4)degrees. Two molecules form a centro-symmetrical pair connected via pi-pi interactions between the pyrrole and pyrone rings [centroid-centroid distance = 3.882 (1) angstrom] and one benzene of the carbazole and the pyrone unit [centroid-centroid distance 3.824 (1) angstrom]. The lattice is stabilized by C-H center dot center dot center dot O bridging to both coumarin O atoms.