WebApr 30, 2007 · In conclusion, the present study is the first application of KF-alumina as a base for the preparation of 2-aminothiophenes by microwave accelerated multi-component condensation. This method offers an efficient and convenient modification to the Gewald reaction as it could be carried out with very short reaction times under microwave … Webappropriate aminothiophene 9. Deamination of aminothiophene 9 via the bromide and following cleavage with Zn in acid media to afford derivative 10 was very efficient, displaying none of side ...
Gewald aminothiophene synthesis SpringerLink
WebSep 28, 2024 · In this study, we demonstrated the synthesis of functionalized 2-aminothiophenes using Gewald-reaction-derived 2-aminothiophenes as the amine substrates, whose low reactivity in the Petasis... The Gewald reaction is an organic reaction involving the condensation of a ketone (or aldehyde when R = H) with a α-cyanoester in the presence of elemental sulfur and base to give a poly-substituted 2-amino-thiophene. The reaction is named after the German chemist Karl Gewald (born 1930). See more The reaction mechanism of the Gewald reaction was elucidated 30 years after the reaction was discovered. The first step is a Knoevenagel condensation between the ketone (1) and the α-cyanoester (2) to produce the stable … See more In one variation of the Gewald reaction a 3-acetyl-2-aminothiophene is synthesized starting from a dithiane (an adduct of sulfur and acetone if R = CH3 or acetaldehyde if R = H) and the sodium salt of cyanoacetone which in itself is very unstable: See more shirt button repair tool
The Gewald multicomponent reaction - PubMed
WebOct 1, 2013 · In 2013, Liang and co-workers proposed for the first time a 2-aminothiophene synthesis following Gewald conditions in water as the solvent in a reaction ignited by sodium polysulfides in catalyst ... WebThe Gewald reaction of sulfur, cyanoacetic acid derivatives, and oxo-component (G-3CR) yielding highly substituted 2-aminothiophene derivatives has seen diverse … WebNovel 3-acetyl-2-aminothiophenes were prepared from cyanoacetone and1,4-dithianyl-2,5-diols using a modified Gewald reaction. The syntheses of thecorresponding acetamides, as well as that of 3-acetyl-2-amino-5-nitrothiophene – aninteresting building-block for thiophene azo dyes – are reported. Detailed spectroscopicinvestigations (1H-NMR, 13C-NMR, MS, … quotes for profile pictures on facebook