Reactivity studies for the synthesis of 5-phenylthiophene-2-carbaldehyde by Suzuki-Miyaura coupling

Abstract

The aim of this work is the synthesis of a formyl-arylthiophene derivative, using simple experimental techniques and commercially available reagents. The synthesis of this compound involves a palladium catalysed cross-coupling reaction (Suzuki-Miyaura coupling), between a boronic acid derivative and a heterocyclic brominated compound using DME as solvent and Na2CO3 as base. Different coupling components would be used in order to determine the influence of the structure of the boronic acid as well as the brominated compound on the yield of the Suzuki-Miyaura coupling reaction. Several experimental techniques will be considered such as heating at reflux under an inert atmosphere, liquid-liquid extraction, gravity and vacuum filtration, thin layer chromatography (TLC), column chromatography on silica gel and melting point. The determination of the structure of the compound synthesized will be also performed through 1H NMR and IR spectroscopic techniques. The duration of the experiment will be 3 sessions: session 1: preparation of 5-phenylthiophene-2-carbaldehyde; session 2: isolation of 5-phenylthiophene-2-carbaldehyde; session 3: purification of 5-phenylthiophene-2-carbaldehyde using column chromatography on silica gel. The difficulty level of this experiment is medium and the level of study is intermediate.