In the title compound, C(27)H(15)Br(2)ClO·C(3)H(7)NO, the xanthene moiety has a flattened boat conformation with a folding angle between the naphthalene units of 9.46 (3)°. The mean planes of the xanthene system and its 4-chloro-phenyl substituent are nearly perpendicular [dihedral angle = 89.43 (5)°]. The dimethyl-formamide solvent mol-ecule is disordered over two sets of sites with an occupan...

Xanthene dyes can be appended to cyclodextrins via an ester or amide bridge in order to switch the fluorescence on or off. This is made possible through the formation of nonfluorescent lactones or lactams as the fluorophore can reversibly cyclize. In this context we report a green approach for the synthesis of switchable xanthene-dye-appended cyclodextrins based on the coupling agent 4-(4,6-dim...

An efficient and eco-friendly method for the one-pot synthesis of 14-aryl-14H-dibenzo [a,i]xanthene-8,13-dione derivatives has been developed in the presence of Fe3O4@SiO2 core-shell nanoparticles. The multi-component reactions of 2-hydroxy-1,4-naphthoquinone, β-naphthol and aldehydes were efficiently catalyzed using novel nano-scale materials under reflux conditions. The present method offers ...

In this study, silica nanoparticles were used as support to prepare a new heterogeneous catalyst system for application in organic reactions. The reaction of silica nanoparticles with sodium 2-bromoethane-1-sulfonate resulted in the connection of a sulfonic acid group on the surface of silica nanoparticles (NSESA). The synthetic catalyst system was characterized using different microscopic and ...

In the xanthene ring system of the title compound, C(23)H(25)BrO(4), the 4H-pyran ring is almost planar [maximum deviation = 0.040 (3) Å] and the cyclo-hexene ring adopts a sofa conformation. The cyclo-hexene ring attached to the xanthene system is puckered [Q(T) = 0.427 (3) Å, θ = 55.0 (4) ° and ϕ = 164.4 (6) °]. In the crystal, mol-ecules are linked to each other by O-H⋯O and C-H⋯O hydrogen b...

In the title compound, C(37)H(40)N(4)O(2), the xanthene and spiro-lactam rings are almost planar, with r.m.s. deviations from the mean planes of 0.223 (2) and 0.057 (2) Å, respectively, and form a dihedral angle of 85.76 (3)°. The dihedral angle between the xanthene mean plane and the benzene ring is 87.16 (5)°. One of the two ethyl groups of one of the diethyl-amino groups is disordered over t...