Crystal structures of 2-benzyl-amino-4-(4-bromo-phen-yl)-6,7,8,9-tetra-hydro-5H-cyclo-hepta-[b]pyridine-3-carbo-nitrile and 2-benzyl-amino-4-(4-chloro-phen-yl)-6,7,8,9-tetra-hydro-5H-cyclo-hepta[b]pyridine-3-carbo-nitrile.

In the title compounds, C24H22BrN3, (I), and C24H22ClN3, (II), the 2-amino-pyridine ring is fused with a cyclo-heptane 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 mol-ecules, forming inversion dimers with R 2 (2)(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 inter-actions [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 inter-actions [inter-centroid distance = 3.771 (2) Å] involving inversion-related pyridine rings, forming a two-dimensional network lying parallel to (001).