10.2174/157017812803521081
The research focuses on the expedited and green synthesis of novel 4-thiazolidinones and new 2,4-disubstituted thiazoles with a tetrahydro carbazole pendant. The purpose of this study is to develop an efficient and environmentally friendly method for synthesizing these heterocyclic compounds, which are known for their biological activities and potential applications in pharmaceuticals and optoelectronic devices. The researchers utilized N-methylpyridinium tosylate, an ionic liquid, as a catalyst for the cyclocondensation reaction of 2-(2,3-dihydro1H-carbazol-4(9H)-ylidene)hydrazinecarbothioamide with α-haloacids, achieving quantitative yields in a short time. They also reported a solvent-free grinding method for the synthesis of 2,4-disubstituted thiazoles. The chemicals used in the process include 2,3-dihydro-1H-carbazol-4(9H)-one, thiosemicarbazide, chloroacetic acid, 2-bromopropionic acid, and substituted phenacyl bromides. The study concludes that the use of the ionic liquid not only simplifies the work-up process but also results in faster reactions and higher yields compared to conventional methods, with the added benefit of being recoverable and reusable for multiple reaction cycles without affecting product yield.
10.1039/c4ob02147a
The research aims to develop a novel and efficient synthetic route for N-glycolyl muramyl dipeptide (MDP), a bacterial glycopeptide of significant interest in the study of nucleotide-binding oligomerization domain-containing protein 2 (NOD2). The traditional synthesis of MDP derivatives involves a challenging SN2 step at the C-3 position of glucosamine derivatives, which is non-reproducible. To address this, the authors devised a new strategy that hinges on the alkylation of benzylidene-protected glucal with 2-bromopropionic acid, bypassing the difficult SN2 step. The subsequent steps include azidonitration and an unusual azide reduction/acylation via an aza ylide/oxaphospholidine intermediate. The study concludes that this 11-step synthetic route is robust and circumvents the traditional difficulties, enabling the synthesis of N-acetyl and N-glycolyl MDP derivatives for further studies on NOD2 binding interactions and kinetics.
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