Synthesis and Structures of Three- and Hexa-armed Benzene Derivatives Featuring Lateral Benzoic Ester and Benzoic Acid Functions

The new 1,3,5-tri-substituted and hexa-substituted benzoic methyl esters 1, 3 and benzoic acids 2, 4 have been synthesized. Single-crystal structure determinations of 1 - 3 are reported, which show specific molecular conformations and packings in the crystal. In all structures, the conformation of the molecules deviates considerably from threefold and sixfold symmetry, respectively. Columnar packings are observed in the crystal structures of the esters 1 and 3, stabilized by weak C-H・・・O and C-H・・・π interactions, while the packing of 2 features the formation of supramolecular strands involving the dimerization of the carboxylic acid group.