51-17-2Relevant articles and documents
Synthesis of a conformationally constrained analogue of BW A78U, an anticonvulsant adenine derivative
Desaubry, Laurent,Wermuth, Camille Georges,Bourguignon, Jean-Jacques
, p. 4249 - 4252 (1995)
The synthesis of a conformationally constrained analogue of the anticonvulsant BW A78U, a 9-benzyl-adenine derivative, has been devised, using silicon tetrachloride in a new cyclodehydration.
Synthesis, Structure, and Luminescent Property of One Zinc(II) Coordination Polymer Constructed from 1H-Benzoimidazole
Zhang, Shu Hua,Zhao, Ru Xia,Li, Gui,Zhang, Hai Yang,Li, He Ping
, p. 804 - 808 (2016)
A new metal-organic coordination polymer [Zn(bm)(AcO)]n (1), where Hbm is 1H-benzoimidazole), has been prepared and structurally characterized by IR, elemental analysis and single-crystal X-ray diffraction. Single-crystal X-ray analysis shows that it crystallizes in the monoclinic space group of P21/c with a = 10.8231(5) ?, b = 9.8329(4) ?, c = 8.8665(4) ?, β = 99.298(4)°, V = 931.20(7) ?3, and X = 4. The bm ligand bridges two adjacent Zn(II) with its two nitrogen atoms to form a one-dimensional chain, which further constructed 2D network through a bridge bidentate AcO- ligand. Furthermore, luminescent property of 1 was investigated.
UV monitoring of microwave-heated reactions - A feasibility study
Getvoldsen, Gareth S.,Elander, Nils,Stone-Elander, Sharon A.
, p. 2255 - 2260 (2002)
UV/Visible spectroscopy has been used to monitor the progress of the formation of benzimidazole from the reaction between 1,2-diaminobenzene and formic acid. The reaction was performed at three concentration levels, each becoming more dilute so that at the most dilute level direct UV monitoring from the reaction sample was possible. At each level the reaction was conducted by conventional and by microwave heating. The success of the microwave reaction at the most dilute levels encourages the construction of a microwave reactor/UV/Vis spectrometer hybrid instrument for the monitoring of this and other reactions.
Haloacetylated enol ethers. 13 [19]. Synthesis of N-[1-aryl(alkyl)-3- oxo-4,4,4-trichloro-1-buten-1-yl]-o-phenylenediamines and 2-trichloromethyl- 4-aryl-3H-1,5-benzodiazepines
Bonacorso, Helio Gauze,Bittencourt, Sandra R. T.,Wastowski, Arci D.,Wentz, Alexandre P.,Zanatta, Nilo,Martins, Marcos A. P.
, p. 45 - 48 (1999)
The synthesis and isolation of the intermediates N-[1-aryl(alkyl)-3- oxo-4,4,4-trichloro-1-buten-1-yl]-o-phenylenediamines 2a-f and the corresponding 2-trichloromethyl-4-aryl-3H-1,5-benzodiazepines 3c-g or benzimidazoles 4a-b derivatives obtained from the intramolecular cyclization of 2a-f or from direct cyclocondensation reaction of β-alkoxyvinyl trichloromethyl ketones 1a-g with o-phenylenediamine, is reported. Depending of the structure of the β-alkoxyvinyl trichloromethyl ketones or the N-[1- aryl(alkyl)-3-oxo-4,4,4-trichloro-buten-1-yl]-o-phenylenediamines and the reactions conditions, benzimidazoles or 3H-1,5-benzodiazepines were obtained.
One-Pot Transformation of Lignin and Lignin Model Compounds into Benzimidazoles
Guo, Tao,He, Jianghua,Liu, Tianwei,Zhang, Yuetao
supporting information, (2022/02/07)
It is a challenging task to simultaneously achieve selective depolymerization and valorization of lignin due to their complex structure and relatively stable bonds. We herein report an efficient depolymerization strategy that employs 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant/catalyst to selectively convert different oxidized lignin models to a wide variety of 2-phenylbenzimidazole-based compounds in up to 94 % yields, by reacting with o-phenylenediamines with varied substituents. This method could take full advantage of both Cβ and/or Cγ atom in lignin structure to furnish the desirable products instead of forming byproducts, thus exhibiting high atom economy. Furthermore, this strategy can effectively transform both the oxidized hardwood (birch) and softwood (pine) lignin into the corresponding degradation products in up to 45 wt% and 30 wt%, respectively. Through a “one-pot” process, we have successfully realized the oxidation/depolymerization/valorization of natural birch lignin at the same time and produced the benzimidazole derivatives in up to 67 wt% total yields.
Sulfoxylate Anion Radical-Induced Aryl Radical Generation and Intramolecular Arylation for the Synthesis of Biarylsultams
Laha, Joydev K.,Gupta, Pankaj
supporting information, p. 4204 - 4214 (2022/03/16)
Aryl radical generation from the corresponding aryl halides using an electron donor and subsequent intramolecular cyclization with arenes could be an important advancement in contemporary biaryl synthesis. A green and practically useful synthetic protocol to access diverse six- and seven-membered biarylsultams especially with a free NH group including demonstration of a gram-scale synthesis is reported herein. The sulfoxylate anion radical (SO2-?), generated in situ from the reagents rongalite or sodium dithionite (Na2S2O4), was found to be the key single electron transfer agent forming aryl radicals from aryl halides, which upon intramolecular arylation gives biarylsultams with good to excellent yields. The approach features generation of aryl radicals that remained underexplored, use of a cheap and readily available industrial reagents, and transition metal-free, mild, and green reaction conditions.
Highly efficient one pot synthesis of benzimidazoles from 2-nitroaniline and PhSiH3 as reducing agent catalyzed by Pd/C as a heterogeneous catalyst
Phatake, Vishal V.,Bhanage, Bhalchandra M.
, (2021/03/15)
This work reports an efficient route for the synthesis of benzimidazole from o-nitroaniline in the presence of carbon dioxide atmosphere, PhSiH3 as a reducing agent catalyzed by Pd/C as a catalyst. Benzimidazoles have become the focus of organic chemists, as benzimidazole is an important intermediate in medicinal chemistry. We have developed more efficient route for the synthesis benzimidazole and various substituted benzimidazoles have been synthesized in good to excellent yield. The TBD (1,5,7-Triazabicyclo [4.4.0] dec-5-ene) is selected as a base as it promotes the CO2 insertion. Benzimidazoles were synthesized through reduction of nitro group followed by cyclization of amine using CO2 as a carbon source. Moreover, the Pd/C catalyst can be recycled up to five recycle run without significant changes in the yield of the product.
Sustainable Synthesis of 2-Hydroxymethylbenzimidazoles using D-Fructose as a C2 Synthon
Raja, Dineshkumar,Philips, Abigail,Sundaramurthy, Devikala,Chandru Senadi, Gopal
supporting information, p. 3754 - 3759 (2021/10/14)
D-fructose, a biomass-derived carbohydrate has been identified as an environmentally benign C2 synthon in the preparation of synthetically useful 2-hydroxymethylbenzimidazole derivatives by coupling with 1,2-phenylenediamines. Proof of concept was established by synthesizing 23 examples using BF3.OEt2 (20 mol%), TBHP (5.5 M, decane) (1.0 equiv.) in CH3CN at 90 °C for 1 h. The pivotal features of this method include metal-free conditions, short time, good functional group tolerance, gram scale feasibility and the synthesis of benzimidazole fused 1,4-oxazine. Control studies with conventional C2 synthons did not produce the desired product, thus suggesting a new reaction pathway from D-fructose.
Application of sulfonic acid fabricated cobalt ferrite nanoparticles as effective magnetic nanocatalyst for green and facile synthesis of benzimidazoles
Yadav, Priyanka,Kakati, Praachi,Singh, Preeti,Awasthi, Satish K.
, (2021/02/06)
This work represents the design and synthesis of efficient sulfonated cobalt ferrite solid acid catalyst. The synthesized solid acid green catalyst was characterized using various techniques viz. FT-IR, powder XRD, SEM, TEM and VSM. The obtained catalyst was used to synthesize biologically significant 2-substituted benzimidazole derivatives by condensation between o-phenylenediamine with various aromatic, aliphatic and heterocyclic aldehydes. High yield (up to 98 %), short reaction time (10?25 min), mild reaction condition, wide functional group tolerance, easy work-up procedure and excellent values of green chemistry metrices such as lower E factor (0.126), high RME value (88.83 %), carbon efficiency (100 %) and high atom economy (AE) value (90.65 %), are some salient features of the present catalytic system. Moreover, the catalyst recovery by simply using an external magnet and catalyst reusability up to 7 times without any significant loss in catalytic efficiency are some additional remarkable features of the current protocol.
Facile N-Formylation of Amines on Magnetic Fe3O4?CuO Nanocomposites
Datta Khanal, Hari,Mishra, Kanchan,Rok Lee, Yong
, p. 4477 - 4484 (2021/08/30)
A facile, eco-friendly, efficient, and recyclable heterogeneous catalyst is synthesized by immobilizing copper impregnated on mesoporous magnetic nanoparticles. The surface chemistry analysis of Fe3O4?CuO nanocomposites (NCs) by XRD and XPS demonstrates the synergistic effect between Fe3O4 and CuO nanoparticles, providing mass-transfer channels for the catalytic reaction. TEM images clearly indicate the impregnation of CuO onto mesoporous Fe3O4. This hydrothermally synthesized eco-friendly and highly efficient Fe3O4?CuO NCs are applied as a magnetically retrievable heterogeneous catalyst for the N-formylation of wide range of aliphatic, aromatic, polyaromatic and heteroaromatic amines using formic acid as a formylating agent at room temperature. The catalytic activity of the NCs for N-formylation is attributable to the synergistic effect between Fe3O4 and CuO nanoparticles. The N-formylated product is further employed for the synthesis of biologically active quinolone moieties.