Crystal structure of flavonoid compounds. I. 4'-Bromoflavanone

Abstract

The molecular structure of 4'-bromoflavanone (C15HllOzBr) has been determined by X-ray diffraction and refined by full-matrix least-squares methods based on 1636 reflections recorded on a Picker FACS-1 automated diffractometer. The final R-index is 0-052 (weighted R is 0.023). The crystals are monoclinic space group P21/c, with cell dimensions a= 6.636 (4), b = 16.522 (10), and c= 11.739 (7) A, fl= 98.00 (3) °.There are four molecules in the unit cell; the molecules are optically active at C(2) of the pyrone ring. The racemic crystal has a d, l pair packed about a center of symmetry. The bromine substituted phenyl ring is equatorially substituted at C(2) with the phenyl ring rotated so that its plane is approximately perpendicular (105.5 ° with respect to the A-ring) to the mean plane of the remainder of the molecule.

7-Hydroxyflavanone (I) and 7-Ethoxycarbonylmethoxyflavanone (II)

“…The most studied are the flavones. In contrast, only a few single-crystal X-ray studies of flavanones have been reported so far (Cantrell, Stalzer & Becker, 1974;Mariezcurrena, 1978;Tomlin & Cantrell, 1990). The spasmolytic activity of a series of flavanone ether derivatives, including (I) and (II), was investigated using efloxate (Ertan, 198 l a) as the reference compound.…”

Interactions in flavanone and chalcone derivatives: Hirshfeld surface analysis, energy frameworks and global reactivity descriptors

“…Based on the results of the CSD search, two flavanone-chalcone pairs were added, thus increasing the total number of halogen-substituted compounds. Finally, the number of compounds was expanded to include the following: CH1 (Serdiuk et al, 2018; CSD refcode REPXIW), CH3 (Fun et al, 2011;URESOA), FL4 (Białoń ska et al, 2007;NUYRII01), CH5 (Fun et al, 2007;QEXLAH), FL6 (Cantrell et al, 1974;BRFLAY20), CH6A/B [two different polymorphs; Agilandeshwari et al (2016) (IKOFAR); Salinas-Ortega et al (2017) (IKOFAR01)], FL7 (Goud et al, 1995;YIVREA) and CH7 (Goud et al, 1995; YIVPUO) (Scheme 1). Unfortunately, in the case of flavanone FL8, the corresponding CIF is not present in the CSD.…”

5,2′-Dihydroxy-7-methoxyflavanone

“…The title compound, a flavanone also known as dihydroechioidinin, was isolated from the whole plant of Andrographis echioides Nees (Acanthaceae), an erect herb widely distributed in the dry districts of tropical India and Sri Lanka (Gamble, 1956). In order to study the biological activity of flavonoids, a number of flavone structures were determined, of which only a few have been reported to date (Cantrell et al, 1974;Tomlin & Cantrell, 1990;Mariezcurrena, 1978;Kendi et al, 1995a,b). Flavonones have recognized spasmolytic, expectorant, antiulcer, liver-protecting and antimicrobial properties (Gaber, 1986).…”