Crystal structures of (1E,4E)-1,5-bis(5-bromothiophen-2-yl)-2,4-dimethylpenta-1,4-dien-3-one and (E)-4-(5-bromothiophen-2-yl)-1,3-diphenylbut-3-en-2-one

The title compounds, C15H12Br2OS2, (I), and C20H15BrOS, (II), were synthesized by employing Claisen–Schmidt condensation of pentan-3-one and dibenzylacetone with 5-bromothiophene-2-carbaldehyde in the presence of methanolic KOH. Even though 1:2 products were expected in both of the reactions, 1:2 an...

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Bibliographic Details
Main Authors: C. Nithya, M. Sithambaresan, M. R. Prathapachandra Kurup
Format: Article
Language:English
Published: International Union of Crystallography 2016-02-01
Series:Acta Crystallographica Section E: Crystallographic Communications
Subjects:
Online Access:http://scripts.iucr.org/cgi-bin/paper?S205698901600058X
Description
Summary:The title compounds, C15H12Br2OS2, (I), and C20H15BrOS, (II), were synthesized by employing Claisen–Schmidt condensation of pentan-3-one and dibenzylacetone with 5-bromothiophene-2-carbaldehyde in the presence of methanolic KOH. Even though 1:2 products were expected in both of the reactions, 1:2 and 1:1 products were obtained as (I) and (II), respectively. In (I), the two methyl groups are trans to each other, 29.5 (7) and 28.7 (7)° away from the central carbonyl bond between them, whereas the two phenyl rings of dibenzylacetone subtend a dihedral angle of 53.09 (18)°. In the crystal of (I), C—H...O hydrogen bonds define molecular chains along c. A second type of molecular chain is formed along b by means of C—Br...π interactions. These two families of molecular chains are stacked by π–π interactions, forming a three-dimensional supramolecular architecture. In (II), similar C—H...O hydrogen bonds as in (I) define inversion dimers, whilst C—H....π interactions build a staircase structure along the a axis.
ISSN:2056-9890