Preparation of thioamide building blocks via microwave-promoted three-component kindler reactions.
A microwave-enhanced variation of the Kindler thioamide synthesis is introduced. Taking advantage of the sealed vessel capabilities of a dedicated single-mode microwave reacto,r a diverse selection of 13 aldehyde and 12 amine precursors was utilized in the construction of a representative 34-member library of substituted thioamides. The three-component condensations of aldehydes, amines, and elemental sulfur were carried out using 1-methyl-2-pyrrolidone (NMP) as solvent employing microwave flash heating at 110-180 degrees C for 2-20 min. A simple workup protocol allows the isolation of synthetically valuable primary, secondary, and tertiary thioamide building blocks in 83% average yield and >90% purity.
Zbruyev
Oleksandr I
OI
Institute of Chemistry, Karl-Franzens-University Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
Stiasni
Nikola
N
Kappe
C Oliver
CO
D001547:Benzaldehydes; D020650:Combinatorial Chemistry Techniques / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008872:Microwaves; D009025:Morpholines / Q000138:chemical synthesis / Q000737:chemistry; D010879:Piperazines / Q000138:chemical synthesis / Q000737:chemistry; D013854:Thioamides / Q000138:chemical synthesis*
D001547:Benzaldehydes; D007202:Indicators and Reagents; D009025:Morpholines; D010879:Piperazines; D013854:Thioamides