Crystal structure of 2,2-dimethyl-N-(5-methyl-pyridin-2-yl)propanamide

There are two mol-ecules in the asymmetric unit of the title compound, C11H16N2O. The pyridine rings and amide groups overlap almost perfectly (r.m.s. overlay fit = 0.053 Å), but the tertiary butyl groups have different orientations: in one mol-ecule, one of the methyl C atoms is syn to the amide O atom [O-C-C-C = -0.8 (3)°] and in the other the equivalent torsion angle is 31.0 (2)°. In the crystal, the two independent mol-ecules are linked by a pair of N-H⋯N hydrogen bonds in the form of an R 2 (2)(8) loop to form a dimer. A C-H⋯O inter-action connects the dimers into [100] chains.

Crystal structure of 2,2-dimethyl-N-(pyridin-3-yl)propanamide

In the title compound, C10H14N2O, the pyridine ring is inclined to the mean plane of the amide moiety [N-C(=O)C] by 17.60 (8)°. There is an intra-molecular C-H⋯O hydrogen bond present involving the carbonyl O atom. In the crystal, mol-ecules are linked via N-H⋯N hydrogen bonds, forming chains propagating along [100]. The tert-butyl group is disordered over two sets of sites with a refined occupancy ratio of 0.758 (12):0.242 (12).

2,2-Dimethyl-N-(4-methyl-pyridin-2-yl)propanamide

In the title compound, C11H16N2O, the dihedral angle between the mean plane of the 4-methypyridine group and the plane of the amide link is 16.7 (1)°, and there is a short intra-molecular C-H⋯O contact. Hydrogen bonding (N-H⋯O) between amide groups forms chains parallel to the b axis. Pairs of methyl-pyridine groups from mol-ecules in adjacent chains are parallel but there is minimal π-π inter-action.