3-Benzoyl­methyl­ene-1-methyl-3,4-dihydro­quinoxalin-2(1H)-one

In the title compound, C₁₇H₁₄N₂O₂, the quinoxaline ring is essentially planar and makes a dihedral angle of 9.1 (2)° with the benzene ring of the benzoyl­methyl­ene group. There are intra­molecular N—H...O hydrogen bonds and inter­molecular C—H...O inter­actions.

1,4-Dimethyl-2-phenyl-3H,10aH-4-azacyclobuta[c]phenylene-3,5-dione

The title compound, C₂₂H₁₇NO₂, was obtained by the photoreaction of N-methyl-1,8-naphthalene­dicarboximide with 1-phenyl­propyne. The planar cyclo­butene ring makes a dihedral angle of 71.7 (2)° with the benzene ring of the 1,2-dihydro­naphthalene group. There are intra­molecular C—H...O hydrogen bonds, and inter­molecular C—H...O inter­actions help to stabilize the crystal structure.

3a,8c-Dichloro-8b-phenyl-3a,3b,8b,8c-tetra­hydro-2-methyl-1H-[1]benzothieno[2′,3′:3,4]cyclo­buta[1,2-c]pyrrole-1,3(2H)-dione

In the title compound, C₁₉H₁₃Cl₂NO₂S, the cyclo­butane ring is slightly folded. The crystal structure is stabilized by intra- and inter­molecular C—H...O inter­actions.