N-tert-Butyl-2-[4-(dimethyl­amino)­phen­yl]imidazo[1,2-a]pyrazin-3-amine

In the title compound, C₁₈H₂₃N₅, the imidazole ring makes a dihedral angles of 3.96 (8) and 19.02 (8)°, respectively, with the pyrazine and benzene rings while the dihedral angle between the pyrazine and benzene rings is 16.96 (7)°. In the crystal, mol­ecules are linked via N—H...N hydrogen bonds, forming chains along [010]. These chains are linked by C—H...N hydrogen bonds, forming two-dimensional networks lying parallel to (001).

N-tert-Butyl-2-(2,6-di­chloro­phen­yl)imidazo[1,2-a]pyrazin-3-amine

In the title compound, C₁₆H₁₆Cl₂N₄, the imidazole ring mean plane makes a dihedral angle of 70.01 (1)° with the phenyl ring. The Cl atoms deviate by −0.0472 (6) and 0.0245 (8) Å from the plane of their attached benzene ring. In the crystal, mol­ecules are linked via pairs of C—H...N hydrogen bonds, forming inversion dimers.

3-[(E)-2-(4-Chloro­phen­yl)ethen­yl]-5,5-di­methyl­cyclo­hex-2-en-1-one

In the title compound, C₁₆H₁₇ClO, the cyclo­hexene ring adopts a half-chair conformation and the best plane through the six ring atoms makes a dihedral angle of 6.69 (7)° with the chlorophenyl ring. In the crystal, pairs of C—H...O hydrogen bonds link the mol­ecules into centrosymmetric R₂²(20) dimers. The dimers are linked into an infinite chains along the b-axis direction by further C—H...O hydrogen bonds.

Allyl 2-(2,2-dimethyl-3a,6a-di­hydro­furo[3,2-d][1,3]dioxol-5-yl)-4-oxo-4H-chromene-3-carboxyl­ate

In the title compound, C₂₀H₁₈O₇, the dioxolane ring adopts an envelope conformation with the dimethyl-substituted C atom as the flap, and its mean plane makes a dihedral angle of 73.25 (2)° with the pyran ring mean plane. The furan ring makes dihedral angles of 67.43 (12) and 6.20 (11)° with the mean plane of the dioxolane and pyran rings, respectively. The O atom attached to the pyran ring deviates by 0.0219 (2) Å from its mean plane. In the crystal, mol­ecules are linked via C—H...O hydrogen bonds, forming chains along [010] and enclosing R₂²(9) loops. They stack along the a axis with π–π inter­actions involving the 4H-chromene units [centroid–centroid distances of 3.6389 (13) and 3.6555 (13) Å]. The terminal CH₂=CH- atoms of the allyl acetate group are disordered over two sets of sites with a refined occupancy ratio of 0.717 (6):0.283 (6).

Methyl 2-(2,2-dimethyl-3a,6a-di­hydro­furo[3,2-d][1,3]dioxol-5-yl)-4-oxo-4H-chromene-3-carboxyl­ate

In the title mol­ecule, C₁₈H₁₆O₇, the dioxolane ring adopts an envelope conformation with the dimethyl-substituted C atom as the flap. The furan ring is almost coplanar with the pyran ring, with a dihedral angle of 1.04 (10)° between the planes, and it makes a dihedral angle of 67.97 (11)° with the mean plane of the dioxolane ring. The latter makes a dihedral angle of 67.15 (10)° with the pyran ring. The O atom attached to the pyran ring deviates by −0.009 (1) Å. The crystal packing features C—H...O hydrogen bonds, forming a three-dimensional structure. The meth­oxy­carbonyl atoms are disordered over two positions, with a refined occupancy ratio of 0.508 (18):0.492 (18).

1-[2-(3-Meth­oxy­phen­yl)eth­yl]pyrroli­dine-2,5-dione

In the title compound, C₁₃H₁₅NO₃, the pyrrolidine ring makes a dihedral angle of 4.69 (9)° with the 3-meth­oxy-phenyl ring. In the crystal, hydrogen-bonded chains running along [101] are generated by connecting neighbouring mol­ecules via C—H...O hydrogen bonds. Parallel chains are linked by further C—H...O hydrogen bonds, forming a three-dimensional structure.

N-(4-Meth­oxy­phen­yl)-2,6-dimethyl-1,3-dioxan-4-amine

In the title compound, C₁₃H₁₉NO₃, the dioxane ring adopts a chair conformation. Its mean plane is inclined to the 4-meth­oxy­phenyl ring by 70.34 (9)°. In the crystal, mol­ecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers with an R²₂(16) ring motif. The dimers are linked via C—H...π inter­actions, forming two-dimensional networks lying parallel to the ac plane.

N-(2-Fluoro­phen­yl)-2,6-dimethyl-1,3-dioxan-4-amine

In the title compound, C₁₂H₁₆FNO₃, the dioxane ring adopts a chair conformation with the methyl groups and amine N atom in equatorial positions. The best plane through the dioxane ring makes a dihedral angle of 43.16 (8)° with the phenyl ring. In the crystal, pairs of C—H...O hydrogen bonds link the mol­ecules into centrosymmetric R₂²(8) dimers, which are linked into [100] chains by further C—H...O hydrogen bonds. The N—H group does not participate in hydrogen bonding.

2,6-Dimethyl-N-(2-methyl­phen­yl)-1,3-dioxan-4-amine

In the title compound, C₁₃H₁₉NO₂, the dioxane ring adopts a chair conformation and its mean plane makes a dihedral angle of 45.36 (8)° with the phenyl ring. In the crystal, mol­ecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with R²₂(12) ring motifs. These dimers are consolidated by pairs of C—H...O hydrogen bonds with R²₂(8) ring motifs.

N-(4-Bromo­phen­yl)-2,6-dimethyl-1,3-dioxan-4-amine

In the title compound, C₁₂H₁₆BrNO₂, the dioxane ring adopts a chair conformation and its mean plane makes a dihedral angle of 60.63 (12)° with the 4-bromo­phenyl ring. In the crystal, mol­ecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with an R₂²(8) ring motif. These dimers are consolidated by pairs of C—H...O hydrogen bonds with an R₂²(16) ring motif. Adjacent dimers are connected via C—H...O hydrogen bonds, forming infinite chains propagating along the c-axis direction.

N-(4-Fluoro­phen­yl)-2,6-dimethyl-1,3-dioxan-4-amine

In the title compound, C₁₂H₁₆FNO₂, the dioxane ring adopts a chair conformation with the methyl substituents and the C—N bond in equatorial orientations. Its mean plane subtends a dihedral angle of 40.17 (6)° with the benzene ring. In the crystal, weak N—H...F hydrogen bonds link the mol­ecules into C(7) chains propagating in [100].