- Synthesis, Characterization and DFT-D Studies of 2-Aminoethoxycalix[4]resorcinarenes: A Novel Heterogeneous Organocatalyst
-
The present article reports the synthesis of two novel supramolecular architectures, Phenyl(octa-2-aminoethoxy)calix[4]resorcinarene and 2-Aminoethoxyphenyl-(octa-2-aminoethoxy)calix[4]resorcinarene via surface functionalization and describes their applic
- Hiba, K.,Shaibuna, M.,Shebitha, A. M.,Sreekumar, K.
-
-
- Heterogeneous palladium (II)-complexed dendronized polymer: A rare palladium catalyst for the one-pot synthesis of 2-arylbenzoxazoles
-
The palladium complex of dendronized amine polymer (EG–Gn–Pd, n = 0, 1 and 2) having ethylene glycol-initiated polyepichlorohydrin as core was synthesized on a Merrifield resin support and was well characterized. Generally, palladium catalysts are known for carbon–carbon coupling reactions. Here, a developed catalyst was found to be good for benzoxazole synthesis. Higher generation dendronized polymer (EG–G2–Pd) was found to be better catalyst over lower generation dendronized polymers. Moreover, dendronized polymers were found to be a better catalyst over dendrigraft polymers. The catalyst reusability was checked and good yield was obtained for five cycles.
- George, Smitha,Sreekumar, Krishnapillai
-
-
- 2-Aryl benzazole derived new class of anti-tubercular compounds: Endowed to eradicate mycobacterium tuberculosis in replicating and non-replicating forms
-
The high mortality rate and the increasing prevalence of Mtb resistance are the major concerns for the Tuberculosis (TB) treatment in this century. To counteract the prevalence of Mtb resistance, we have synthesized 2-aryl benzazole based dual targeted molecules. Compound 9m and 9n were found to be equally active against replicating and non-replicating form of Mtb (MIC(MABA) 1.98 and 1.66 μg/ml; MIC(LORA) 2.06 and 1.59 μg/ml respectively). They arrested the cell division (replicating Mtb) by inhibiting the GTPase activity of FtsZ with IC50 values 45 and 64 μM respectively. They were also capable of kill Mtb in non-replicating form by inhibiting the biosynthesis of menaquinone which was substantiated by the MenG inhibition (IC50 = 11.62 and 7.49 μM respectively) followed by the Vit-K2 rescue study and ATP production assay.
- Datta, Dhrubajyoti,Debnath, Joy,Franzblau, Scott G.,Ghosh, Kalyan Sundar,Hari, Natarajan,Ma, Rui,Rana, Shiwani,Velappan, Anand Babu
-
-
- Development of homogeneous polyamine organocatalyst for the synthesis of 2-aryl-substituted benzimidazole and benzoxazole derivatives
-
A new polyamine was prepared by the ring opening polymerization of epichlorohydrin and properly characterized. The catalytic property of the prepared polymer was assessed by synthesizing 2-aryl-substituted benzimidazole and benzoxazole derivatives by the conjugation of o-phenylenediamine/o-aminophenol with various aromatic aldehydes in the presence of atmospheric oxygen. Significant attributes of the present synthesis include short reaction time, good to excellent yield, high purity, easy reusability, and room temperature reaction. The reaction was carried out in the absence of any metal catalyst and other cooxidants.
- Kottayil, Hiba,Machingal, Shaibuna,Parackal B., Sherly mole,Alungal M., Shebitha,Theresa, Letcy V.,Govindan, Avudaiappan,Krishnapillai, Sreekumar
-
p. 3310 - 3317
(2020/07/17)
-
- In-vitro Anti-cancer assay and apoptotic cell pathway of newly synthesized benzoxazole-N-heterocyclic hybrids as potent tyrosine kinase inhibitors
-
A series of benzoxazole-N-heterocyclic hybrids have been synthesized by a one-pot strategy. Molecular docking study revealed that such compounds have the ability to inhibit enzyme protein tyrosine kinase. The findings of this work have been the successful synthesis of benzoxazole scaffolds, featuring hybrids of benzoxazole with quinoline and quinoxaline respectively. The molecular docking studies have showed these compounds to be inhibitors of tyrosine kinase enzyme which triggers growth of cancer cells. The cytotoxicity study of compounds 4a-f showed better potency against breast cancer cell lines MCF-7 and MDA-MB-231 in contrast to oral and lung cancer cell lines KB and A549. The tyrosine kinase activity was measured using Universal Tyrosine Kinase Assay kit using horseradish peroxide (HRP)-conjugated anti-phosphotyrosine kinase solution as a substrate. The compounds 4c exhibited maximum inhibition in the activity of enzyme tyrosine kinase with IC50 value 0.10 ± 0.16 μM, than other compounds which were studied and thus proved to be inhibitors of enzyme tyrosine kinase. The selective index of all four compounds was found out to be greater than two, indicating the non-toxic behaviour, i.e. good anti-cancer activity. Further, fluorescence microscopic study helped to characterize the mode of cell death, which was found to be late apoptosis as indicated by the orange fluorescence. The SAR analysis has also been carried out.
- Desai, Sulaksha,Desai, Vidya,Shingade, Sunil
-
supporting information
(2019/11/13)
-
- Sulfur-Promoted Synthesis of Benzoxazoles from 2-Aminophenols and Aldehydes
-
Elemental sulfur (S8) was found to be an excellent stoichiometric oxidant to promote oxidative condensation of 2-aminophenols with a wide range of aldehydes, including aliphatic aldehyde such as cyclohexanecarboxaldehyde. The reactions were catalyzed by sodium sulfide in the presence of DMSO as an additive. The benzoxazole products were obtained in satisfactory yields. The reaction conditions could be applied to larger syntheses (10–50 mmol).
- Nguyen, Le Anh,Dang, Thai Duy,Ngo, Quoc Anh,Nguyen, Thanh Binh
-
supporting information
p. 3818 - 3821
(2020/06/10)
-
- Continuous flow/waste-minimized synthesis of benzoxazoles catalysed by heterogeneous manganese systems
-
Herein, we present our results on the development of a waste minimized protocol for the synthesis of 2-arylbenzoxazoles in continuous flow. Manganese-based heterogeneous catalysts were used in combination with cyclopentylmethyl ether as an environmentally friendly and safe reaction medium. The use of oxygen promotes the oxidative process ensuring at the same time a complete regeneration of the catalyst adopting a flow configuration which does not include the use of an additional mechanical pump. These features allowed for a faster synthesis compared to batch procedures with minimal metal leaching.
- Ferlin, Francesco,Van Der Hulst, Mitchell K.,Santoro, Stefano,Lanari, Daniela,Vaccaro, Luigi
-
supporting information
p. 5298 - 5305
(2019/10/11)
-
- Synthesis of Benz-Fused Azoles via C-Heteroatom Coupling Reactions Catalyzed by Cu(I) in the Presence of Glycosyltriazole Ligands
-
Glycosyl triazoles are conveniently accessible and contain multiple metal-binding units that may assist in metal-mediated catalysis. Azide derivatives of d-glucose have been converted to their respective aryltriazoles and screened as ligands for the synthesis of 2-substituted benz-fused azoles and benzimidazoquinazolinones by Cu-catalyzed intramolecular Ullmann type C-heteroatom coupling. Good to excellent yields for a variety of benz-fused heterocyles were obtained for this readily accessible catalytic system.
- Mishra, Nidhi,Singh, Anoop S.,Agrahari, Anand K.,Singh, Sumit K.,Singh, Mala,Tiwari, Vinod K.
-
supporting information
p. 389 - 399
(2019/05/06)
-
- Synthesis and biological evaluation of acylthiourea against DUSP1 inhibition
-
Structure based virtual screening attempts to discover DUSP1 inhibitors have yielded a scaffold featuring benzoxazole and acylthiourea pharmacophore. A series of its analogues were synthesized to explore structure activity relationship (SAR) of DUSP1 inhi
- Yeon Kim, Bo,Hee Yoon, Ji,Kim, Myeongbin,Nyoung Kim, Jae,Park, Hwangseo,Eon Ryu, Seong,Lee, Sangku
-
supporting information
p. 1746 - 1748
(2019/05/21)
-
- Method for synthesizing benzoxazole through microwave radiation of benzamide compound in water phase
-
The invention discloses a method for synthesizing benzoxazole through microwave radiation of a benzamide compound in a water phase. The benzamide compound is added into the water phase under the microwave condition to be subjected to a cyclization reaction for generating the benzoxazole under the alkali condition, and the method for preparing the benzoxazole is environmentally friendly, easy and convenient to operate, safe, low in cost and efficient. Compared with the prior art, the method can be applied to a large number of functional groups, the yield is high, the number of by-products is small, and the method is easy to operate, safe, low in cost and environmentally friendly. (Please see the specifications for the formula).
- -
-
Paragraph 0043
(2019/03/08)
-
- Method used for rapid preparation of benzo-heterocycle compound with physical grinding under solvent-free room temperature conditions
-
The invention discloses a method used for rapid preparation of benzo-heterocycle compound with physical grinding under solvent-free room temperature conditions. According to the method, glacial aceticacid is taken as a catalyst; at solvent-free room temperature conditions, physical grinding is adopted, reaction of 2-substituted arylamines (2-mercapto arylamine, 2-aminophenol, and o-phenylenediamine) and aromatic aldehydes is carried out using physical grinding. The method is friendly to the environment, is simple in operation, is safe, is low in cost, and is high in efficiency. Compared withthe prior art, the advantages are that: the method is suitable for a large amount of functional groups, yield is high, less by-product is generated, operation is simple, the method is safe, cost is low, and the method is friendly to the environment.
- -
-
Paragraph 0062; 0085
(2019/01/21)
-
- Palladium(II) Immobilized Onto the Glucose Functionalized Magnetic Nanoparticle as a New and Efficient Catalyst for the One-pot Synthesis of Benzoxazoles
-
Palladium(II) have been immobilized into the nano magnetic Fe3O4 which was functionalized with glucose in order to achieve a one-pot synthesis of 2-substituted benzoxazole derivatives with high yields in the diverse range of organic solvents. The nano catalyst is highly dispersive in polar solvents and can be easily recovered and reused for 6 runs without significant loss of its activity. Finally, the catalyst was fully characterized by FT-IR, TGA, CHN, SEM, EDX and atomic absorption spectroscopy.
- Moghaddam, Firouz Matloubi,Saberi, Vahid,Kalhor, Sepideh,Veisi, Nazila
-
-
- A 2 - substituted benzoxazole compound of preparation method (by machine translation)
-
The invention discloses a method for preparing a 2-substituted benzoxazole compound, and belongs to the technical field of synthesis of benzoxazole compounds. According to the technical scheme, the method is characterized by comprising the steps that an aldehyde compound R1CHO and an ortho-aminophenol compound (please see the specification for the formula) are dissolved in solvent xylene or methylbenzene, and pre-reacting is conducted for one hour when the solvent is heated to be at the temperature of 120 DEG C; then the temperature is lowered to be an indoor temperature, catalyst copper acetylacetonate is added, and negative pressure suction is carried out in the oxygen atmosphere for reacting till TLC monitors that the reacting is complete; filtering is performed, and water and ethyl acetate are added in filter liquor to be extracted; an organic phase is dried through anhydrous sodium sulfate, column chromatography purification is carried out after the solvent is removed by steaming, and accordingly the 2-substituted benzoxazole compound (please see the specification for the formula) is obtained. According to the method, the aldehyde compound and the ortho-aminophenol compound are used as reacting raw materials, the copper acetylacetonate is used as a catalyst, oxygen is used as an oxidizing agent, no extra additives are needed, and a series of 2-substituted benzoxazole compounds are synthesized; operation is simple and practicable, the raw materials are cheap and easy to get, reaction efficiency is high and repeatability is good.
- -
-
Paragraph 0027; 0028
(2018/01/05)
-
- Anti-bacterial, catalytic and docking behaviours of novel di/trimeric imidazolium salts
-
Flexible di/trimeric substituted imidazolium salts are prepared under conventional/solvent free silica supported approaches. Solid supported approaches are superior than the conventional method like environment friendly, higher yield, shorter reaction time and easy workup procedure. We have studied the catalytic activities of our synthesized di/trimeric imidazolium salts for one-pot preparation of benzoxazole derivatives under conventional/Muffle furnace conditions. We have monitored the efficiency of recycled flexible di/trimeric imidazolium salts up to fourth cycles showed excellent responses. We have studied the MIC and MBC of our di/trimeric imidazolium salts against Gram positive/negative microorganisms under micro dilution method. Nitro substituted imidazolium salts showed excellent screening responses than the unsubstituted compounds. Computer assisted docking analysis is carried out for all our synthesized compounds. The host-guest interaction via hydrogen bonding between standard and our drug molecules against various human Gram positive and negative pathogens are compared. From the docking analysis, our drug molecules showed effective interaction against test pathogens.
- Ganapathi, Pandurangan,Ganesan, Kilivelu
-
p. 452 - 464
(2017/03/24)
-
- Magnetic Co-doped NiFe2O4 Nanocomposite: A Heterogeneous and Recyclable Catalyst for the One-Pot Synthesis of Benzimidazoles, Benzoxazoles and Benzothiazoles under Solvent-Free Conditions
-
A simple and efficient procedure for the synthesis of benzimidazoles, benzoxazoles, and benzothiazoles via the condensation of o-phenylenediamine, o-aminophenol, and o-aminothiophenol with various benzaldehydes by using magnetic Co-doped NiFe2O4 nanoparticles has been developed. This nanocatalyst has advantages such as excellent product yields, solvent-free conditions, and very short reaction times. After any experiment, the magnetic nanocatalyst could be easily separated with the aid of an external magnet and reused at least four times without any loss of its catalytic performance.
- Karimian, Azam,Mohammadzadeh Kakhki, Roya,Kargar Beidokhti, Hamideh
-
p. 1316 - 1325
(2017/11/22)
-
- A comparative study of the catalytic activity of Co- and CoFe2O4-NPs in C-N and C-O bond formation: synthesis of benzimidazoles and benzoxazoles from o-haloanilides
-
Nanoparticles of cobalt ferrite (CoFe2O4-NPs) and pure cobalt (Co-NPs) were synthesized, and after characterization, their catalytic activities for dehalogenative intramolecular C-O and C-N bond formation reactions were investigated and compared. These inexpensive and efficient catalysts enabled creation of new methods for the synthesis of benzimidazoles and benzoxazoles in green media, with ligand-free and mild reaction conditions. All the reactions resulted in moderate to excellent yields under the optimized reaction conditions; however, the reactions using Co-NPs as the catalyst were completed in relatively shorter reaction times. Furthermore, analysis showed that the reusability of the two catalytic systems is approximately comparable.
- Hajipour, Abdol R.,Khorsandi, Zahra
-
p. 10474 - 10481
(2016/12/07)
-
- A mild, efficient and reusable solid phosphotungestic acid catalyst mediated synthesis of benzoxazole derivatives: A grinding approach
-
Background: The development of efficient methodologies for the preparation of benzoxazole and its derivatives has gained a lot of importance in current research. There are many methods are reported for the synthesis of benzoxazoles includes condensation of 2-aminophenol with carboxylic acid. Traditional methods also have several side reactions, non renewable oxidative reagents and solvents which negatively affect the environmentally and eco-friendly nature of the reaction. We have developed PTA catalyzed synthesis of 2-arylbenzoxazole from 2-aminophenols with different aromatic aldehydes using a grinding strategy in excellent yield. Methods: The synthesis of benzoxazoles in high yields by using silica supported Rangappa S. Keri PTA/PTA as solid acid catalyst at room temperature using grinding method. Results: Aromatic aldehydes which have electron donating or electron withdrawing groups were also investigated and as expected it gives good to excellent yield of products, it can be seen that electron donating and electron withdrawing groups does not show any difference on their action yields. Conclusion: We have developed PTA catalyzed synthesis of 2-arylbenzoxazole from 2-aminophenols with different aromatic aldehydes using a grinding strategy in excellent yield. The use of this reusable catalyst under solvent-free conditions has made this protocol practical, environmentally friendly and economically attractive. The simple work-up procedure, the short reaction times the mild reaction conditions, the high yields of products and the non-toxicity of the catalyst are other advantages of the present method. This protocol approaches combines the advantages of both focused library synthesis and diversity oriented synthesis because of the simplification of reaction protocol that we have been developed.
- Patil, Mahadeo R.,Yelamaggad, Aditya,Keri, Rangappa S.
-
p. 474 - 481
(2016/11/19)
-
- KMnO4/HOAc system promoted one-pot synthesis of benzoxazoles from o-aminophenols or oxidative cyclization of o-hydroxyarylidene anilines at room temperature
-
1,3-Benzoxazoles via oxidative cyclization of corresponding o-hydroxyarylidene anilines was synthesized in the presence of KMnO4/HOAc system. This system also was applied for the one-pot synthesis of 1,3-benzoxazoles from o-amino phenols and aldehydes. The both protocols were processed at room temperature under solvent-free conditions with good to excellent yields.
- Mirjalili,Bamoniri,Bagheri
-
p. 809 - 814
(2016/04/05)
-
- Palladium catalyzed Csp2-H activation for direct aryl hydroxylation: The unprecedented role of 1,4-dioxane as a source of hydroxyl radicals
-
A novel strategy for direct aryl hydroxylation via Pd-catalysed Csp2-H activation through an unprecedented hydroxyl radical transfer from 1,4-dioxane, used as a solvent, is reported with bio relevant and sterically hindered heterocycles and various acyclic functionalities as versatile directing groups.
- Seth, Kapileswar,Nautiyal, Manesh,Purohit, Priyank,Parikh, Naisargee,Chakraborti, Asit K.
-
p. 191 - 194
(2015/01/09)
-
- Trichloroisocyanuric Acid/Triphenylphosphine-Mediated Synthesis of Benzimidazoles, Benzoxazoles, and Benzothiazoles
-
A new and efficient method for preparation of benzimidazoles, benzoxazoles, and benzothiazoles from reactions of different carboxylic acids with o-phenylenediamine, o-aminophenol, and o-aminothiophenol in the presence of triphenylphosphine/trichloroisocyanuric acid system is presented. The desired products have been characterised on the basis of spectral (infrared, NMR, mass spectrometry) data, and the mechanism of their formation is proposed. The remarkable advantages are the inexpensive and readily available reagent, simple procedure, mild conditions, and good-to-excellent yields.
- Rezazadeh, Soodabeh,Akhlaghinia, Batool,Razavi, Nasrin
-
p. 145 - 155
(2015/05/05)
-
- Ag@TiO2 nanocomposite; Synthesis, characterization and its application as a novel and recyclable catalyst for the one-pot synthesis of benzoxazole derivatives in aqueous media
-
In the present study, we use a Ag@TiO2 nanocomposite for the efficient synthesis of benzoxazole derivatives via the one-pot condensation of 2-aminophenol and several aromatic aldehydes or orthoesters or carboxylic acids or amides or acyl chlorides in water at room temperature. In all situations the preferred products were synthesized with excellent yields. The short reaction times, high yields, safety and mild conditions, simplicity, non-toxicity and easy workup are the main merits of this protocol.
- Maleki, Behrooz,Baghayeri, Mehdi,Vahdat, Seyed Mohammad,Mohammadzadeh, Abbas,Akhoondi, Somaieh
-
p. 46545 - 46551
(2015/06/16)
-
- Graphene oxide as a heterogeneous reagent promoted synthesis of 2-substituted 1,3-benzazoles in water
-
An efficient chemical method for the synthesis of benzimidazoles, benzothiazoles, and benzoxazoles has been developed through the condensation of various aldehydes with o-phenylenediamine, o-aminothiophenol, and o-aminophenol using graphene oxide (GO) as an oxidant in water. These benzazoles are also prepared through a one-pot oxidation/condensation tandem process by reacting alcohols with 2-amino-(thio)phenol/aniline in the presence of GO in poly(ethylene glycol) as a safe media. Moreover, this carbonaceous material could be readily separated using a simple filtration.
- Khalili, Dariush,Banazadeh, Ali Reza
-
p. 1693 - 1706
(2016/01/26)
-
- Magnetically separable nano CeO2: A highly efficient catalyst for ligand free direct C-H arylation of heterocycles
-
An efficient, ligand free, nano CeO2-Fe3O4 catalyzed direct C-H arylation of heteroarenes such as benzoxazole and benzothiazole has been carried out with aryl halides in DMSO or arenediazonium salts in water. The catalyst exhibited high activity with moderate to excellent product yields under mild reaction conditions. Nano CeO2-Fe3O4 was synthesized and characterized by SEM, TEM, EDAX, XRD, FTIR, DSC-TGA, and ICP-MS analyses. The catalytic activity and stability of the catalyst were excellent, even after the ten cycle of recyclability
- Shelkar, Radheshyam S.,Balsane, Kishor E.,Nagarkar, Jayashree M.
-
supporting information
p. 693 - 699
(2015/01/30)
-
- Ligand-free direct C-arylation of heterocycles with aryl halides over a metal-organic framework Cu2(BPDC)2(BPY) as an efficient and robust heterogeneous catalyst
-
A crystalline porous metal-organic framework Cu2(BPDC) 2(BPY) was synthesized and characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), atomic absorption spectrophotometry (AAS), hydrogen temperature-programmed reduction (H2-TPR), and nitrogen physisorption measurements. The Cu2(BPDC)2(BPY) exhibited high catalytic activity in direct CH arylation reactions between heterocyles and aryl halides. The Cu 2(BPDC)2(BPY)-catalyzed CH arylation reaction could proceed to higher conversion than that of the reaction using Cu 3(BTC)2, Cu(BDC), Cu(BPDC), and Cu2(BDC) 2(BPY) as catalyst. Furthermore, under our conditions, the Cu 2(BPDC)2(BPY) also exhibited significantly higher activity than that of common copper salts, including Cu(NO3)2, CuCl, CuCl2, and CuI. Excellent reusability of the Cu-MOF in the direct heterocycle CH arylation reaction was achieved.
- Le, Hanh T.N.,Nguyen, Tung T.,Vu, Phuong H.L.,Truong, Thanh,Phan, Nam T.S.
-
-
- Tri-lacunary polyoxometalates of Na8H[PW9O 34] as heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation and the synthesis of benzoxazole derivatives
-
We reported for the first time the development of tri-lacunary polyoxometalates (POMs) of Na8H[A-PW9O34] ·7H2O and Na8H[B-PW9O 34]·19H2O (Na-A-PW9 and Na-B-PW 9) as highly selective and efficient heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation of various aldehydes and ketones and the synthesis of benzoxazole derivatives at 25 C under mild conditions. Since both Na-A-PW9 and Na-B-PW9 display no characteristic porosity, it is proposed that the catalytic reactions proceed not only on the surface and interface, but also in the bulk phase. The catalysts can be easily recovered and reused for at least six times without obvious decrease of catalytic activities and the structures of the catalysts remain unchanged after recycling. The easy preparation, high efficiency, reusability of the heterogeneous catalysts of Na-A-PW9 and Na-B-PW9 exhibit great potential for further application.
- Zhao, Shen,Chen, Yang,Song, Yu-Fei
-
p. 140 - 146
(2014/03/21)
-
- One-pot synthesis of 2-substituted benzoxazoles promoted by copper acetate monohydrate
-
An efficient synthesis of 2-substituted benzoxazoles via copper acetate monohydrate oxidative coupling of aldehydes with o-aminophenol is described. This synthetic strategy has some advantages as simple procedure, inexpensive and easily available catalyst, and facile isolation of the products in moderate to good yields.
- Chen, Guo-Feng,Shen, Hai-Dong,Zhang, Li-Yan,Li, Hong-Yang,Lan, Rui-Jia,Chen, Bao-Hua,Li, Ji-Tai,Hu, Qing-Hui
-
p. 180 - 187
(2014/05/20)
-
- Nano ceria catalyzed synthesis of substituted benzimidazole, benzothiazole, and benzoxazole in aqueous media
-
A series of substituted benzimidazoles, benzothiazoles, and benzoxazoles was synthesized by combining 1,2-phenylenediamine, 2-aminothiophenol, or 2-aminophenol with aryl, heteroaryl, aliphatic, α,β-unsaturated aldehydes in the presence of nano ceria (CeO2) as an efficient heterogeneous catalyst.
- Shelkar, Radheshyam,Sarode, Sachin,Nagarkar, Jayashree
-
supporting information
p. 6986 - 6990
(2013/12/04)
-
- Palladium-catalyzed desulfitative C-arylation of a benzo[d]oxazole C-H bond with arene sulfonyl chlorides
-
A palladium-catalyzed direct desulfitative C-arylation of a benzo[d]oxazole C-H bond with arene sulfonyl chlorides is described. The procedure tolerates halo, cyano, nitro, trifluoromethyl, acetyl and acetylamino groups on the phenyl ring of sulfonyl chlorides, providing the arylation products in moderate to good yields. It represents a practical and attractive alternative for the synthesis of 2-aryl benzoxazoles.
- Zhang, Manli,Zhang, Shouhui,Liu, Miaochang,Cheng, Jiang
-
supporting information; experimental part
p. 11522 - 11524
(2011/11/12)
-
- Zn(OAc)2 · 2H2O-catalyzed, simple, and clean procedure for the synthesis of 2-substituted benzoxazoles using a grindstone method
-
Zn(OAc)2 · 2H2O efficiently catalyzes the condensation reaction between 2-aminophenol and various araldehydes to afford the 2-substituted benzoxazoles in good to excellent yields. The remarkable features of this protocol are simple and mild reaction conditions, use of readily available catalyst, and shorter reaction time, and in addition the reaction proceeds just by grinding the substrates and catalyst without any solvent and hence matches the green chemistry protocols.
- Madhusudana Reddy,Nizam, Aatika,Pasha
-
experimental part
p. 1838 - 1842
(2011/06/23)
-
- An efficient procedure for the synthesis of benzoxazole and benzothiazole derivatives using a H2O2/SiO2-FeCl3 system
-
A series of benzoxazole and benzothiazoles was readily prepared from the reaction of ortho-aminophenol/ortho-aminothiophenol and aldehydes using solid silica supported ferric chloride (SiO2-FeCl3) as catalyst followed by oxidation with H2O2 under ambient conditions. Some of advantages of this method are a simple and convenient procedure, easy purification, and shorter reaction times. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Mosslemin, Mohammad Hossein,Fazlinia, Abbas
-
experimental part
p. 2165 - 2170
(2011/01/12)
-
- Design and synthesis of 2-arylbenzimidazoles and evaluation of their inhibitory effect against Chlamydia pneumoniae
-
Chlamydia pneumoniae is an intracellular bacterium that responds poorly to antibiotic treatment. Insufficient antibiotic usage leads to chronic infection, which is linked to disease processes of asthma, atherosclerosis, and Alzheimer's disease. The Chlamydia research lacks genetic tools exploited by other antimicrobial research, and thus other approaches to drug discovery must be applied. A set of 2-arylbenzimidazoles was designed based on our earlier findings, and 33 derivatives were synthesized. Derivatives were assayed against C. pneumoniae strain CWL-029 in an acute infection model using TR-FIA method at a concentration of 10 μM, and the effects of the derivatives on the host cell viability were evaluated at the same concentration. Fourteen compounds showed at least 80% inhibition, with only minor changes in host cell viability. Nine most potential compounds were evaluated using immunofluorescence microscopy on two different strains of C. pneumoniae CWL-029 and CV-6. The N-[3-(1H-benzimidazol-2-yl)phenyl]-3-methylbenzamide (42) had minimal inhibitory concentration (MIC) of 10 μM against CWL-029 and 6.3 μM against the clinical strain CV-6. This study shows the high antichlamydial potential of 2-arylbenzimidazoles, which also seem to have good characteristics for lead compounds.
- Keurulainen, Leena,Salin, Olli,Siiskonen, Antti,Kern, Jan Marco,Alvesalo, Joni,Kiuru, Paula,Maass, Matthias,Yli-Kauhaluoma, Jari,Vuorela, Pia
-
p. 7664 - 7674
(2011/03/17)
-
- Ligand-free copper-catalyzed synthesis of substituted benzimidazoles, 2-aminobenzimidazoles, 2-aminobenzothiazoles, and benzoxazoles
-
(Chemical Equation Presented) The synthesis of substituted benzimidazoles, 2-aminobenzimidazoles, 2-aminobenzothiazoles, and benzoxazoles is described via intramolecular cyclization of o-bromoaryl derivatives using copper(II) oxide nanoparticles in DMSO under air. The procedure is experimentally simple, general, efficient, and free from addition of external chelating ligands. It is a heterogeneous process and the copper(II) oxide nanoparticles can be recovered and recycled without loss of activity. 2009 American Chemical Society.
- Saha, Prasenjit,Ramana, Tamminana,Purkait, Nibadita,Ali, Md. Ashif,Paul, Rajesh,Punniyamurthy, Tharmalingam
-
supporting information; experimental part
p. 8719 - 8725
(2010/02/28)
-
- ANTIBACTERIAL AGENTS
-
The application concerns compounds for use as antibacterial agents, processes for their preparation, and compositions comprising said agents, wherein said compounds have formula (VI) and r, p, R1, R2, R3 and R4
- -
-
Page/Page column 36
(2009/07/25)
-
- Direct arylation of oxazole and benzoxazole with aryl or heteroaryl halides using a palladium-diphosphine catalyst
-
Through the use of PdCl(dppb)(C3H5) as a catalyst, a range of aryl bromides and chlorides undergoes coupling via C-H bond activation/functionalization reaction with oxazole or benzoxazole in good yields. This air-stable catalyst can be used at low loadings with several substrates. Surprisingly, better results in terms of substrate/catalyst ratio were obtained in several cases using electron-excessive aryl bromides than with the electron-deficient ones. This seems to be mainly due to the relatively low thermal stability of some of the 2-arylbenzoxazoles formed with electron-deficient aryl halides. With these substrates, in order to obtain higher yields of product, the reactions had to be performed at a lower temperature (100-120 °C) using a larger amount of catalyst. On the other hand, in the presence of the most stable products, the reactions were performed at 150 °C using as little as 0.2 mol% catalyst. Arylation of benzoxazole with heteroaryl bromides also gave the coupling products in moderate to high yields using 0.2-5 mol% catalyst. With this catalyst, electron-deficient aryl chloride such as 4-chlorobenzonitrile, 4-chloroacetophenone or 2-chloronitrobenzene have also been used successfully.
- Derridj, Fazia,Djebbar, Safia,Benali-Baitich, Ouassini,Doucet, Henri
-
p. 135 - 144
(2008/03/30)
-
- 2,3-Dihydro-1,3-dioxo-1H-isoindole-5-carboxylic acid derivatives: A novel class of small molecule heparanase inhibitors
-
A novel class of 2,3-dihydro-1,3-dioxo-1H-isoindole-5-carboxylic acids are described as inhibitors of the endo-β-glucuronidase heparanase. Several of the compounds, for example, 2-[4-propylamino-5-[5-(4-chloro)phenyl-benzoxazol-2- yl]phenyl]-2,3-dihydro-1,3-dioxo-1H-isoindole-5-carboxylic acid (9c), display potent heparanase inhibitory activity (IC50 200-500nM) and have high selectivity (>100-fold) over human β-glucuronidase. They also show anti-angiogenic effects. Such compounds should serve as useful biological tools and may provide a basis for the design of novel therapeutic agents.
- Courtney, Stephen M.,Hay, Philip A.,Buck, Richard T.,Colville, Claire S.,Porter, David W.,Scopes, David I. C.,Pollard, Faye C.,Page, Martin J.,Bennett, James M.,Hircock, Margaret L.,McKenzie, Edward A.,Stubberfield, Colin R.,Turner, Paul R.
-
p. 3269 - 3273
(2007/10/03)
-
- SUBSTITUTED PHENYLUREA DERIVATIVES AS HDAC INHIBITORS
-
A series of phenylurea derivatives, further substituted on the phenyl ring by a benzoxazole, benzothiazole or benzimidazole moiety, being inhibitors of histone deacetylase, are accordingly of use in medicine, in particular for the treatment of cancer.
- -
-
-
- Synthesis of Fused Ring Heterocycles from Aromatic Amines with Hydroximoyl Chlorides
-
Substituted 2-arylbenzimidazoles, 2-arylbenzoxazoles and 2-arylbenzothiazoles were obtained in good yield by the reaction of hydroximoyl chlorides with ortho-substituted aromatic amines.The benzo moiety of the benzimidazoles was shown by nmr to be symmetrical, indicating that the N-H groupo proton of the imidazole ring is exchanging with water protons in the DMSO-d6 solvent.
- Abdelhamid, Abdou O.,Parkanyi, Cyril,Rashid, S. M. Khaledur,Lloyd, Winston D.
-
p. 403 - 405
(2007/10/02)
-
- BARIUM MANGANATE OXIDATION IN ORGANIC SYNTHESIS: PART III: OXIDATION OF SCHIFF'S BASES TO BENZIMIDAZOLES, BENZOXAZOLES AND BENZTHIAZOLES
-
The oxidative cyclisation of benzylideneamino anilines, phenols and thiophenols to benzimidazoles, benzoxazoles and benzthiazoles respectively using barium manganate is described.
- Srivastava, R. G.,Venkataramani, P. S.
-
p. 1537 - 1544
(2007/10/02)
-