Synthesis and biological evaluation of some differently substituted 9,10-anthracenediones

Synthesis and Solid State Structure of Fluorous Probe Molecules for Fluorous Separation Applications

A series of colored hydrocarbon and fluorocarbon tagged 1-fluoro-4-alkylamino-anthraquinones and 1,4-bis-alkylamino-anthraquinone probe molecules were synthesized from a (fluorinated) alkyl amine and 1,4-difluoroanthraquinone to aid in the development of fluorous separation applications. The anthraquinones displayed stacking of the anthraquinone tricycle and interdigitation of the (fluorinated) alkyl chains in the solid state. Furthermore, intramolecular N-H···O hydrogen bonds forced the hydrocarbon and fluorocarbon tags into a conformation pointing away from the anthraquinone tricycle, with the angle of the tricycle plane normal and the main (fluorinated) alkyl vector ranging from 1 to 39°. Separation of the probe molecules on fluorous silica gel showed that the degree of fluorination of the probe molecules plays only a minor role with most eluents (e.g., hexane-ethyl acetate and methyl nonafluorobutyl ethers-ethyl acetate). However, toluene as eluent caused a pronounced separation by degree of fluorination for fluorocarbon, but not hydrocarbon tagged probe molecules on both silica gel and fluorous silica gel. These studies suggest that hydrocarbon and fluorocarbon tagged anthraquinones are useful probe molecules for the development of laboratory scale fluorous separation applications.

Halophenol Rearrangement in Lewis Acid-Catalyzed Friedel - Crafts Conditions: Evidence of Competitive Initial Protonation and Acylation

Halogen rearrangement was observed during the Lewis acid-catalyzed Friedel–Crafts reaction of phthalic anhydride with bromophenols or bromoanisole. Further investigation revealed that 2-, 3-, and 4-bromophenols undergo rearrangement into other isomers under these reaction conditions. Product distribution from these reactions suggested that halogen rearrangement takes place during the s-complex intermediate of the condensation step. Furthermore, iodophenol undergoes hydrodeiodination rapidly rather than rearrangement, whereas chlorophenol does not undergo rearrangement at all.