Crystal structures of 2-benzylamino-4-(4-bromophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile and 2-benzylamino-4-(4-chlorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile

In the title compounds, C24H22BrN3, (I), and C24H22ClN3, (II), the 2-aminopyridine ring is fused with a cycloheptane ring, which adopts a half-chair conformation. The planes of the phenyl and benzene rings are inclined to that of the central pyridine ring [r.m.s. deviations = 0.0083 (1) and 0.0093 (1) Å for (I) and (II), respectively] by 62.47 (17) and 72.51 (14)°, respectively, in (I), and by 71.44 (9) and 54.90 (8)°, respectively, in (II). The planes of the aromatic rings are inclined to one another by 53.82 (17)° in (I) and by 58.04 (9)° in (II). In the crystals of both (I) and (II), pairs of N—H...Nnitrile hydrogen bonds link the molecules, forming inversion dimers with R22(12) ring motifs. In (I), the resulting dimers are connected through C—H...Br hydrogen bonds, forming sheets parallel to (10-1), and π–π interactions [inter-centroid distance = 3.7821 (16) Å] involving inversion-related pyridine rings, forming a three-dimensional network. In (II), the resulting dimers are connected through π–π interactions [inter-centroid distance = 3.771 (2) Å] involving inversion-related pyridine rings, forming a two-dimensional network lying parallel to (001).