Experimental

R factor = 0.040; wR factor = 0.118; data-to-parameter ratio = 15.6. In the title compound, C19H14FN3O3, the central pyran ring adopts a boat conformation with the O atom and the quaternary C atom diagonally opposite displaced by 0.068 (1) and 0.075 (1) Å, respectively, above the mean plane defined by the other four ring atoms. The co-planar atoms of the pyran ring and the fluorophenyl ring are nearly perpendicular, as evidenced by the dihedral angle of 87.11 (1). The amine group forms an intramolecular N— H O(nitro) hydrogen bond. In the crystal, molecules are linked into parallel chains along [100] by weak N—H N and C—H N(nitro) hydrogen bonds, generating C(8) and C(9) graph-set motifs, respectively. Related literature For the biological activity of substituted pyran derivatives, see: Lokaj et al. (1990); Marco et al. (1993). Some 4H-pyran deri-vatives are potential bioactive compounds and can be used as calcium antagonists, see: Suárez et al. (2002). For hydrogen-bonding graph-set motifs, see: Bernstein et al. (1995). For ring conformation analysis, see: Cremer & Pople (1975). The title compound and some related compounds are widely used as organic intermediates in organic chemistry (Liang et al., 2009). For related structures, see: Nesterov et al. (2004); Nesterov & Viltchinskaia (2001). For a description of the Cambridge Structural Database, see: Allen (2002). For standard bond lengths, see: Allen et al. (1987)