Syntheses and Br…π supramolecular interactions in the crystal structure of ipriflavone bromides

摘要

Two novel compounds, 3,8-dibromo-2-methoxyl-7-isopropoxyisoflavanone (1) and 3,6-dibromo-2-methoxyl-7-isopropoxyisoflavanone (2), are synthesized via bromination reaction of their precursor ipriflavone in methanol.The mixture of 1 and 2 co-crystallizes in ethanol and forms two different crystal shapes, the shape of 1 being block and 2 prism, they can be separated manually.1 and 2 are characterized by IR, 1H NMR and single crystal X-ray diffraction.The mechanism of bromination reaction is also discussed.1 crystallizes in the monoclinic space group P 21 with cell parameters a=1.3569(3) nm, b=0.6706(2) nm, c=2.0704(4) nm, β=97.50(2)°, V=1.8678(6) nm3, Z=4, Dc=1.672 Mg/m3, R=0.0455, wR=0.0779, F(000)=936.2 crystallizes in the monoclinic space group P 21/c with cell parameters a =1.3854(17) nm, b=1.1215(14) nm, c=1.3038(17) nm, β=103.71(2)°, V=1.968(4) nm3, Z=4, Dc=1.587 Mg/m3, R=0.0306, wR=0.0619, F(000)=936.The Br…π interactions, hydrogen bonds, aromatic hydrogen bonds and aromatic stacking interactions exist in the crystal structures of 1 and 2, which lead them into supramolecular compounds with a three-dimensional network structure, respectively.1 and 2 are the isoflavanone derivatives halogenated at C3 and this kind of isoflavanone halides has not been reported yet.