Syntheses and crystal structures of two soybean isoflavone derivatives

Abstract

Two soybean isoflavone derivatives, 7-methoxy-4′-hydroxyisoflavone (1) and 4′, 7-diethoxyl-5-hydroxyisoflavone (2) were synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Two derivatives crystallize in the monoclinic crystal system, space group P21/c. The cell dimensions of 1 are a = 8.696(4) A, b = 11.947(5) A, c = 12.078(5) A, β = 93.594(7)∘, D c = 1.423 Mg/m3, V = 1252.3(10) A3, Z = 4, and those of 2 are a = 37.672(12) A, b = 11.228(4) A, c = 7.582 (3) A, β = 94.150(6)∘, D c = 1.355 Mg/m3, V = 3198.6(18) A3 and Z = 8. They have the same isoflavone skeleton which is composed of a benzopyranone moiety and a phenyl moiety. Hydrogen bonding and π π stacking interactions assemble 1 into supramolecule with a three-dimensional network. And in the crystal structure of 2, hydrogen bonding and C–H ⋅s π stacking interactions lead to the formation of a two-dimensional network.