1849-01-0Relevant articles and documents
Carbonylation of o-phenylenediamine and o-aminophenol with dimethyl carbonate using lead compounds as catalysts
Fu, Yue,Baba, Toshihide,Ono, Yoshio
, p. 91 - 97 (2001)
Lead compounds are active catalysts for carbonylation and carbonylation/methylation of o-phenylenediamine and o-aminophenol with dimethyl carbonate (DMC). 2-Benzimidazolone was obtained in 84% yield by the reaction of o-phenylenediamine with DMC for 1 h at 443 K in the presence of Pb(NO3)2. In the presence of Pb(OAc)2, the reaction quantitatively gave 1,3-dimethyl-2-benzimidazolone, which was formed by methylation of the primary product, 2-benzimidazolone, at 473 K. The effects of reaction variables on the yields of 2-benzimidazolone and 1,3-dimethyl-2-benzimidazolone were examined. The reaction of o-aminophenol with DMC selectively gave a carbonylation product, 2-benzoxazolone, or a carbonylation/methylation product, 3-methyl-2-benzoxazolone, depending on the reaction conditions in the presence of Pb(OAc)2.
Discovery of a Highly Selective Sigma-2 Receptor Ligand, 1-(4-(6,7-Dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)butyl)-3-methyl-1H-benzo[d]imidazol-2(3H)-one (CM398), with Drug-Like Properties and Antinociceptive Effects In Vivo
Avery, Bonnie A.,Chin, Frederick T.,Intagliata, Sebastiano,King, Tamara I.,Matsumoto, Rae R.,McCurdy, Christopher R.,McLaughlin, Jay P.,Mesangeau, Christophe,Seminerio, Michael,Sharma, Abhisheak,Wilson, Lisa L.
, (2020)
The sigma-2 receptor has been cloned and identified as Tmem97, which is a transmembrane protein involved in intracellular Ca2+ regulation and cholesterol homeostasis. Since its discovery, the sigma-2 receptor has been an extremely controversial target, and many efforts have been made to elucidate the functional role of this receptor during physiological and pathological conditions. Recently, this receptor has been proposed as a potential target to treat neuropathic pain due to the ability of sigma-2 receptor agonists to relieve mechanical hyperalgesia in mice model of chronic pain. In the present work, we developed a highly selective sigma-2 receptor ligand (sigma-1/sigma-2 selectivity ratio > 1000), 1-(4-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)butyl)-3-methyl-1H- benzo[d]imidazol-2(3H)-one (CM398), with an encouraging in vitro and in vivo pharmacological profile in rodents. In particular, radioligand binding studies demonstrated that CM398 had preferential affinity for sigma-2 receptor compared with sigma-1 receptor and at least four other neurotransmitter receptors sites, including the norepinephrine transporter. Following oral administration, CM398 showed rapid absorption and peak plasma concentration (Cmax) occurred within 10?min of dosing. Moreover, the compound showed adequate, absolute oral bioavailability of 29.0%. Finally, CM398 showed promising anti-inflammatory analgesic effects in the formalin model of inflammatory pain in mice. The results collected in this study provide more evidence that selective sigma-2 receptor ligands can be useful tools in the development of novel pain therapeutics and altogether, these data suggest that CM398 is a suitable lead candidate for further evaluation.
Study of unsaturated azoles. 16 Synthesis and reactions of 2-styrylbenzimidazoles
Popov
, p. 949 - 953 (1997)
Fusion of 1-methyl-2-styrylbenzimidazole with KOH leads to separation of the phenylvinyl or the N-methyl group to give 1-methylbenzimidazol-2-one or 2-styrylbenzimidazole in the ratio 1:1. Decomposition of the perbromides of benzimidazoles by heating in water gives 5(6)-bromobenzimidazoles and, in the presence of KI, to 5(6)-iodobenzimidazoles. Methods are presented for the synthesis of 5(6)-bromo- and 5(6)-iodo-2-styryl- and also 2-α-bromo- and 2-α-iodostyrylbenzimidazoles. 1998 Plenum Publishing Corporation.
Direct Synthesis of N-Monosubstituted Benzimidazol-2-ones via Ph 3P-I 2-Mediated Reaction of Hydroxamic Acids
Hongsibsong, Surat,Pattarawarapan, Mookda,Phakhodee, Wong,Wiriya, Nittaya,Yamano, Dolnapa
, (2022/03/01)
A facile approach for the synthesis of benzimidazolones via a Ph3P-I2 promoted reaction of hydroxamic acids is reported. Upon Lossen-type rearrangement of the O-activated hydroxamic acids, the in situ generated isocyanates undergo an intramolecular attack by ortho N-nucleophiles producing the cyclized products in good yields under mild conditions. The method allows the direct preparation of a single regioisomer of N-monosubstituted derivatives using readily accessible starting materials and low-cost reagents with broad substrate scope.
Iron-Catalyzed Intramolecular C—H Amidation of N-Benzoyloxyureas
Zhong, Dayou,Wu, Lin-Yang,Wang, Xing-Zhen,Liu, Wen-Bo
, p. 855 - 858 (2021/02/16)
A redox-neutral Fe-catalyzed intramolecular C—H amidation of N-benzoyloxyureas is described. This methodology employs a simple iron complex in situ generated from Fe(OTf)2 and bipyridine as the catalyst and N-benzoyloxyureas as the nitrene prec
Efficient Amination of Activated and Non-Activated C(sp3)?H Bonds with a Simple Iron–Phenanthroline Catalyst
Jarrige, Lucie,Zhou, Zijun,Hemming, Marcel,Meggers, Eric
supporting information, p. 6314 - 6319 (2021/02/01)
A readily available catalyst consisting of iron dichloride in combination with 1,10-phenanthroline catalyzes the ring-closing C?H amination of N-benzoyloxyurea to form imidazolidin-2-ones in high yields. The C?H amination reaction is very general and applicable to benzylic, allylic, propargylic, and completely non-activated aliphatic C(sp3)?H bonds, and it also works for C(sp2)?H bonds. The surprisingly simple method can be performed under open flask conditions.
Methylenation for Aldehydes and Ketones Using 1-Methylbenzimidazol-2-yl Methyl Sulfone
Ando, Kaori,Oguchi, Mai,Kobayashi, Takahisa,Asano, Haruka,Uchida, Nariaki
, p. 9936 - 9943 (2020/09/04)
The methylenation reagent 1-methylbenzimidazol-2-yl methyl sulfone 2 reacts with various aldehydes and ketones in the presence of t-BuOK (room temperature, 1 h) in dimethylformamide to give the corresponding terminal alkenes generally in high yields. For sensitive substrates, the reaction is better carried out at low temperature using sodium hexamethyldisilazide in 1,2-dimethoxyethane. The byproduct is easily removed from the products, and the reaction conditions are mild and practical. Reagent 2 can be easily prepared from commercially available 2-mercaptobenzimidazole 5 in 95% yield without any expensive reagents.
Photocatalytic Intramolecular C-H Amination Using N-Oxyureas as Nitrene Precursors
Ivanovich, Ryan A.,Polat, Dilan E.,Beauchemin, André M.
supporting information, p. 6360 - 6364 (2020/09/02)
Nitrenes are remarkable high-energy chemical species that enable direct C-N bond formation, typically via controlled reactions of metal-stabilized nitrenes. Here, in contrast, the combined use of photocatalysis with careful engineering of the precursor enabled C-H amination forming imidazolidinones and related nitrogen heterocycles from readily accessible hydroxylamine precursors. Preliminary mechanistic results are consistent with the formation of free carbamoyl triplet nitrenes as reactive intermediates.
An Improved Synthesis of Urea Derivatives from N -Acylbenzotriazole via Curtius Rearrangement
Agrahari, Anand K.,Singh, Anoop S.,Singh, Sumit K.,Tiwari, Vinod K.,Yadav, Mangal S.
, p. 3443 - 3450 (2019/09/07)
The good leaving tendency of the benzotriazole moiety has been exploited for the synthesis of symmetric, unsymmetric, N -acyl, and cyclic ureas in good yields from N -acylbenzotriazoles by treating the latter with various amines in the presence of TMSN 3 /Et 3 N in a sealed tube. The salient features of the devised protocol includes the high-yield, mild, metal-free, one-pot reaction conditions, and short reaction time. Furthermore, in many cases, no column chromatography is required for the purification.
Selenium-Catalyzed Carbonylative Synthesis of 2-Benzimidazolones from 2-Nitroanilines with TFBen as the CO Source
Qi, Xinxin,Zhou, Rong,Peng, Jin-Bao,Ying, Jun,Wu, Xiao-Feng
supporting information, p. 5161 - 5164 (2019/01/25)
A selenium-catalyzed carbonylative reaction for the synthesis of 2-benzimidazolones from 2-nitroanilines has been developed. In this strategy, to avoid the usage of toxic CO gas, TFBen (benzene-1,3,5-triyl triformate) was used as a solid and stable CO precursor, and a variety of desired 2-benzimidazolones were produced in moderate to excellent yields.
