Crystal structure and Hirshfeld surface analysis of ()-4-({[2-(benzo[]thio-phen-3-yl)cyclo-pent-1-en-1-yl]meth-yl}(phen-yl)amino)-4-oxobut-2-enoic acid.

In the title compound, CHNOS, the cyclopentene ring adopts an envelope conformation. In the crystal, mol-ecules are linked by C-H⋯π inter-actions, forming ribbons along the axis. Inter-molecular C-H⋯O hydrogen bonds connect these ribbons to each other, forming layers parallel to the (01) plane.

Application of the intramolecular Diels-Alder vinylarene (IMDAV) reaction for the synthesis of benzo-, carbocyclo-, thienothiopheneisoindolecarboxylic acids and its limitations.

Thienylallylamines, readily accessible from the corresponding thienyl aldehydes, react with maleic and trifluoromethylmaleic anhydrides leading to the formation of acids with a thieno[2,3-]isoindole core. The reaction sequence involves two successive steps: acylation of the nitrogen atom of the initial allylamine and the intramolecular Diels-Alder vinylarene (IMDAV) reaction. The scope and limitations of the proposed method were thoroughly investigated.

Crystal structure and Hirshfeld surface analysis of 10-hy-droxy-2-(4-meth-oxy-phen-yl)-3-oxo-2,3,3a,4,10,10a-hexa-hydro-1-9-thia-2-aza-cyclo-penta-[]fluorene-4-carb-oxy-lic acid dimethyl sulfoxide- monosolvate.

In the title compound, CHNOS·CDOS, the central six-membered ring has a slightly distorted boat conformation, while the fused pyrrolidine ring adopts an envelope conformation. These conformations are stabilized by O-H⋯O hydrogen bonds between the main compound and solvent mol-ecules. In addition, intra-molecular C-H⋯O hydrogen bonds in the main mol-ecule form two (6) rings.

Crystal structure and Hirshfeld surface analysis of 4-cyano--[(4-cyano-phen-yl)sulfon-yl]--[2-(5-methyl-furan-2-yl)phen-yl]benzene-sulfonamide.

In the title compound, CHNOS, intra-molecular π-π inter-actions [centroid-to-centroid distance = 3.5640 (9) Å] are observed between the furan and benzene rings of the 4-cyano-phenyl group. In the crystal, mol-ecules are connected C-H⋯O and C-H⋯N hydrogen bonds, forming layers parallel to the (100) plane.