No abstract

Novel carbazolyl-oxazolones, 3a-d, were synthesized with 3-[N-(2-hydroxycarbonylmethyl)-carboxamide]-4-methyl-9H-carbazole and several aryl aldehydes for the first time. Photo physical characterization of synthesized 2-carbazolyl-4-arylidene-5-oxazolones (3a-d) in dichloromethane, chloroform, and toluene was performed.

The asymmetric unit of the title compound, C18H11NO2S, contains two crystallographically independent mol­ecules. In one mol­ecule, the oxazole and thio­phene rings are oriented at dihedral angles of 17.40 (9) and 18.18 (7)° with respect to the naphthalene ring system, while the oxazole and thio­phene rings are oriented to each other at a dihedral angle of 0.86 (9)°. In the other mol­ecule, the corresponding angles are 3.05 (8), 9.62 (6) and 7.02 (8)°, respectively. In each mol­ecule, a weak intra­molecular C—H⋯N hydrogen bond links the oxazole N atom to the naphthalene group. Weak inter­molecular C—H⋯O hydrogen bonding is present in the crystal structure. π–π stacking between the oxazole and thio­phene rings, between the thio­phene and naphthalene rings, and between the oxaozole and naphthalene rings, [centroid–centroid distances = 3.811 (2), 3.889 (2), 3.697 (2) and 3.525 (2) Å] may further stabilize the crystal structure.

In the title compound, C15H15NO3, the carbazole skeleton includes an eth­oxy­carbonyl group at the 3-position. In the indole ring system, the benzene and pyrrole rings are nearly coplanar, forming a dihedral angle of 0.89 (4)°. The cyclo­hexenone ring has an envelope conformation. In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a three dimensional network. A weak C—H⋯π inter­action is also observed.

In the title compound, C24H15NO2, the oxazole ring is oriented at dihedral angles of 10.09 (4) and 6.04 (4)° with respect to the mean planes of the naphthalene ring systems, while the two naphthalene ring systems make a dihedral angle of 4.32 (3)°. Intra­molecular C—H⋯N hydrogen bonds link the oxazole N atom to the naphthalene ring systems. In the crystal, inter­molecular weak C—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. π–π contacts between the oxazole and naphthalene rings and between the naphthalene ring systems [centroid–centroid distances = 3.5947 (9) and 3.7981 (9) Å] may further stabilize the crystal structure. Three weak C—H⋯π inter­actions also occur.