Crystal structure and Hirshfeld surface analysis of two imidazo[1,2-a]pyridine derivatives: N-tert-butyl-2-(4-methoxyphenyl)-5-methylimidazo[1,2-a]pyridin-3-amine and N-tert-butyl-2-[4-(dimethylamino)phenyl]imidazo[1,2-a]pyridin-3-amine

Abstract

In the title imidazo[1,2-a]pyridine derivatives, N-tert-butyl-2-(4-methoxyphenyl)-5-methylimidazo[1,2-a]pyridin-3-amine, C19H23N3O, (I), and N-tert-butyl-2-[4-(dimethylamino)phenyl]imidazo[1,2-a]pyridin-3-amine, C19H24N4, (II), the 4-methoxyphenyl ring in (I) and the 4-(dimethylamino)phenyl ring in (II) are inclined to the respective imidazole rings by 26.69 (9) and 31.35 (10)°. In the crystal of (I), molecules are linked by N—H...N hydrogen bonds, forming chains propagating along the [001] direction. The chains are linked by C—H...π interactions, forming layers parallel to the (010) plane. In (II), the crystal packing also features N—H...N hydrogen bonds, which together with C—H...N hydrogen bonds link molecules to form chains propagating along the c-axis direction. The chains are linked by C—H...π interactions to form layers parallel to the (100) plane. Inversion-related layers are linked by offset π–π interactions [intercentroid distance = 3.577 (1) Å]. The intermolecular interactions of both compounds were analyzed using Hirshfeld surface analysis and two-dimensional fingerprint plots.

Keywords

• crystal structure
• imidazole
• imidazo[1,2-a]pyridine derivatives
• N—H...N hydrogen bonding
• C—H...π interactions
• offset π–π interactions
• Hirshfeld surface analysis
• fingerprint plots