906532-86-3Relevant academic research and scientific papers
Copper-catalyzed intramolecular N-arylation of ureas in water: a novel entry to benzoimidazolones
Barbero, Nekane,Carril, Mónica,SanMartin, Raul,Domínguez, Esther
, p. 7283 - 7288 (2008/09/21)
The copper-catalyzed intramolecular N-arylation of 2-bromoarylureas performed in water leading to the benzo[d]imidazolone framework is reported. The scope of the methodology presented herein proved to?be broad and afforded a significant number of benzoimidazolones in good to excellent yields. The reported protocol is based on the use of CuI and TMEDA acting both as the ligand and as the base in a water solution, which allows for the easy separation of the catalyst containing aqueous phase from the products by simple extraction. Additionally, the N- versus O-arylation competitive processes are also discussed.
Efficient access to cyclic ureas via Pd-catalyzed cyclization
McLaughlin, Mark,Palucki, Michael,Davies, Ian W.
, p. 3311 - 3314 (2007/10/03)
An efficient regioselective method for the preparation of structurally diverse imidazopyridinones and benzoimidazolones starting from readily available and economical starting materials is described. High-yielding reductive alkylation of electron-deficient o-haloarylamines followed by treatment with inexpensive N-chlorosulfonyl isocyanate afforded primary ureas in good overall yields. A Pd-catalyzed urea cyclization reaction furnished imidazopyridinones and benzoimidazolones in excellent yields. Overall, the developed chemistry provides rapid access to pharmaceutically important heterocyclic compounds with high efficiency.
New 2-piperazinylbenzimidazole derivatives as 5-HT3 antagonists. Synthesis and pharmacological evaluation
Orjales, Aurelio,Mosquera, Ramón,Labeaga, Luis,Rodes, Rosa
, p. 586 - 593 (2007/10/03)
A series of 2-piperazinylbenzimidazole derivatives were prepared and evaluated as 5-HT3 receptor antagonists. Their 5-HT3 receptor affinities were evaluated by radioligand binding assays, and their abilities to inhibit the 5-HT-induced Bezold-Jarisch reflex in anesthetized rats were determined. Compound 7e (lerisetron, pK(i) = 9.2) exhibited higher affinity for the 5- HT3 receptor than did tropisetron and granisetron, while compound 7q (pK(i) = 7.5) had very low affinity for this receptor, showing that substitution on the N1 atom of the benzimidazole ring is essential for affinity and activity. The effect of substitution on the aromatic ring of benzimidazole by several substituents in different positions is also discussed. A strong correlation between the 5-HT3 antagonistic activity of the studied compounds and the position of substitution on the aromatic ring was established. Thus, while the 4-methoxy derivative 7m showed weak affinity for the 5-HT3 receptor (pK(i) = 6.7), the 7-methoxy derivative 7n exhibited the highest affinity (pK(i) = 9.4). Compounds 7e and 7n are now under further investigation as drugs for the treatment of nausea and emesis evoked by cancer chemotherapy and radiation.
