Knoevenagel Condensation between 2-Methyl-thiazolo[4,5-<i>b</i>]pyrazines and Aldehydes

Abstract

Knoevenagel condensation, an olefin-forming reaction from active methyl/methylene-containing compounds and aldehydes, is a fundamental and useful synthetic method. Benzothiazoles are, however, out of the scope of Knoevenagel condensation. Here, we report that Knoevenagel condensation between aldehydes and 2-methyl-thiazolo[4,5-b]pyrazines (MeTPy), a fused ring structure comprising pyrazine and thiazole, proceeded smoothly, despite minor structural differences from benzothiazoles. This finding will be useful for short synthesis of MeTPy-containing functional molecules, such as a tau probe analog 1.

Characterization and Molecular Docking of Cinnamic Acid Derivatives: Potential Inhibitors of Cyclooxygenase Enzymes

“…Five derivatives of cinnamic acid were successfully synthesized. Malonic acid and derivatives of benzaldehydes were used in the synthesis of cinnamic acid and derivatives following the Knoevenagel condensation reaction [15]. An equivalent weight of 13.6 g of paramethoxybenzaldehyde and 10.4 g of malonic acid was transferred into a 50 mL volumetric flask with the addition of 25 mL pyridine.…”

Facile Condensation of 2‐Aminobenzaldehydes into Azolo[4,5‐b]Quinolones

“…[8,9] The synthesis of such compounds is typically multistep and complicated. [10][11][12] Therefore, there is a demand for general and straightforward methods for their creation is in demand. Recently, we have discovered a reaction 2-amino-arylidenethiazolidin-2,4-diones with titanium tetrachloride, which leads to the formation of thiazolo [4,5-b]quinolin-2(4H)-ones through desalkylation on nitrogen atom followed by condensation (Scheme 2).…”

“…The synthesis of such compounds is typically multistep and complicated [10–12] . Therefore, there is a demand for general and straightforward methods for their creation is in demand.…”