- Visible-Light Carbon Nitride-Catalyzed Aerobic Cyclization of Thiobenzanilides under Ambient Air Conditions
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A metal-free heterogeneous photocatalysis has been developed for the synthesis of benzothiazoles via intramolecular C-H functionalization/C-S bond formation of thiobenzanilides by inexpensive graphitic carbon nitride (g-C3N4) under visible-light irradiation. This reaction provides access to a broad range of 2-substituted benzothiazoles in high yields under an air atmosphere at room temperature without addition of a strong base or organic oxidizing reagents. In addition, the catalyst was found to be stable and reusable after five reaction cycles.
- Bai, Jin,Yan, Sijia,Zhang, Zhuxia,Guo, Zhen,Zhou, Cong-Ying
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p. 4843 - 4848
(2021/06/28)
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- Design, synthesis and biological evaluation of new benzoxazolone/benzothiazolone derivatives as multi-target agents against Alzheimer's disease
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In this study, four series of compounds with benzoxazolone and benzothiazolone cores were designed, synthesized and evaluated as multifunctional agents against Alzheimer's disease (AD). Additionally, in order to shed light on the effect of the carbonyl groups of benzoxazolone/benzothiazolone, benzoxazole/benzothiazole-containing analogues were also synthesized and evaluated. Inhibition potency of all final compounds towards cholinesterase enzymes and their antioxidant activity were tested. Subsequently, the anti-inflammatory activity, cytotoxicity, apoptosis, and Aβ aggregation inhibition tests were also performed for selected compounds. The results indicated that compounds 11c, a pentanamide derivative with benzothiazolone core, and 14b, a keton derivative with benzothiazolone core, were considered as promising multi-functional agents for further investigation against AD. The reversibility, kinetic and molecular docking studies were also performed for the compounds with the highest AChE 14b (eeAChE IC50 = 0.34 μM, huAChE IC50 = 0.46 μM) and BChE 11c (eqBChE IC50 = 2.98 μM, huBChE IC50 = 2.56 μM) inhibitory activities.
- Erdogan, Merve,Kilic, Burcu,Sagkan, Rahsan Il?kc?,Aksakal, Fatma,Ercetin, Tugba,Gulcan, Hayrettin O.,Dogruer, Deniz S.
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- NCS/TBHP promoted C2 arylation of benzothiazoles with aldehydes in DMSO
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A N-chlorosuccinimide catalyzed oxidative synthesis of 2-aryl benzothiazole from benzothiazoles and aryl aldehydes using tert-butyl peroxybenzoate as an oxidant in dimethyl sulfoxide (DMSO) has been developed in moderate to good yields. Solvent DMSO as a strong Lewis base plays an efficient role in the reaction. Various substrates were tolerated under optimized conditions affording the arylated products in 12–94% yields for 28 examples. Additionally, acylated benzothiazoles were produced with 4 examples.
- Xu, Wen-Xiu,Ye, Fei-Xia,Liu, Xing-Hai,Weng, Jian-Quan
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- Preparation method of substituted benzothiazole C2 arylated derivative
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The invention discloses a substituted benzothiazole C2 arylated derivative and a preparation method thereof. The preparation method comprises the following steps: mixing substituted benzothiazole represented by a formula (II) and substituted benzaldehyde represented by a formula (III); adding a free radical initiator N-chlorosuccinimide (NCS) and an oxidant tert-butyl hydroperoxide (TBHP), carrying out a stirring reaction for about 12 h at 120 DEG C in a nitrogen atmosphere by using DMSO as a solvent, and after the reaction is finished, separating and purifying the reaction liquid to prepare the substituted benzothiazole C2 arylated derivative represented by a formula (I). The invention provides a new method for synthesizing a benzothiazole C2 arylated derivative by taking an NCS/TBHP double component as an oxidation system through a stirring and reaction for about 12 hours at 120 DEG C in a nitrogen atmosphere under the assistance of a strong Lewis base DMSO; and according to the method, an NCS/TBHP double-component oxidation system and an aprotic solvent are selected, and the method has the advantages of being simple in catalytic system, good in product yield and wide in substrate range.
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Paragraph 0057-0058
(2020/05/02)
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- Riboflavin as Photoredox Catalyst in the Cyclization of Thiobenzanilides: Synthesis of 2-Substituted Benzothiazoles
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Benzothiazoles are synthesized from thiobenzanilides using riboflavin as a photosensitizer and potassium peroxydisulfate as a sacrificial oxidizing agent under visible light irradiation. The methodology accepts a broad range of functional groups and affords the 2-substituted benzothiazoles by transition-metal-free organic photoredox catalysis under very mild conditions.
- Bouchet, Lydia M.,Heredia, Adrián A.,Argüello, Juan E.,Schmidt, Luciana C.
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supporting information
p. 610 - 614
(2020/01/31)
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- Copper-Catalyzed Benzylic C—H Functionalization, Oxidation and Cyclization of Methylarenes: Direct Access to 2-Arylbenzothiazoles
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The direct C—H functionalization of methylarenes is of great significance. Herein, a copper-catalyzed oxidative C—N/C—S bond formation through benzylic C(sp3)—H functionalization, oxidation and cyclization of methylarenes is reported. Various 2-arylbenzothiazoles have been synthesized in moderate to excellent yields with readily available o-iodoaniline, potassium sulfide, and methylarenes as raw materials.
- Yu, Wentao,Wu, Wanqing,Jiang, Huanfeng
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p. 1158 - 1166
(2019/10/22)
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- Method used for rapid preparation of benzo-heterocycle compound with physical grinding under solvent-free room temperature conditions
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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.
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Paragraph 0062; 0174
(2019/01/21)
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- A medicine intermediate 2 - aryl benzo thiazole synthetic method of compound (by machine translation)
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The invention relates to a kind of the following formula (III) is shown in the 2 - aryl benzo thiazole compound synthesis method, The method includes: in the three-component composite in the solvent, the catalyst, in the presence of alkali and accelerator, the following formula (I) compound with the following formula (II) compound to react, thus get the states the type (III) compound, Wherein R1 , R2 Are each independently selected from H, C1 - C6 Alkyl, C1 - C6 Alkoxy, halogen or nitro; X is halogen. The method through the catalyst, alkali, accelerator and three-component solvent system selected, combined, so as to play a unique synergy, achieved excellent product yield, has industrial application in the medical field of the actual value. (by machine translation)
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Page/Page column 6-9
(2018/03/01)
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- Method for preparing benzothiazole compound through microwave catalysis in water phase
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The invention discloses a method for preparing a benzothiazole compound through/under microwave catalysis in a water phase. A water-soluble coordination compound is used as a catalyst, and a reactionof inorganic sulfide, 2-iodoaniline and aldehyde is efficiently catalyzed through microwaves in a pure water phase. The method for preparing the benzothiazole compound is environmentally friendly, convenient to operate, safe, cheap and efficient. Compared with the prior art, the method is applied to a large quantity of functional groups, high in yield, simple to operate, safe, low in cost and environmentally friendly and produces a few byproducts.
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Paragraph 0045; 0047
(2018/05/16)
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- Direct arylation of benzoazoles with aldehydes utilizing metal-organic framework Fe3O(BDC)3 as a recyclable heterogeneous catalyst
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A metal-organic framework Fe3O(BDC)3 was synthesized and used as a recyclable heterogeneous catalyst for the direct arylation of azoles with benzaldehydes. Following this protocol, inexpensive and commercially available benzaldehydes could act as an aryl source for the transformation, replacing the aryl halides normally employed in the conventional cross-coupling reactions. The catalyst disclosed higher catalytic productivity for the formation of aryl-substituted azoles than various MOFs and diverse homogeneous iron catalysts. The conversion was considerably regulated by the solvent and the oxidant, and the combination of N-methyl-2-pyrrolidone with di-tert-butyl peroxide offered the best yield. Heterogeneous catalysis was verified for the reaction, and the production of aryl-substituted azoles was only feasible in the presence of the iron framework. It was possible to reuse the catalyst for the direct arylation of azoles with aldehydes while its catalytic activity was preserved for multiple cycles. To our best judgment, this direct arylation of azoles with aldehydes utilizing solid catalysts has not been previously reported.
- Doan, Son H.,Nguyen, Khoa D.,Nguyen, Tung T.,Phan, Nam T. S.
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p. 1423 - 1431
(2017/01/21)
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- Copper-catalyzed multicomponent reactions of 2-iodoanilines, benzylamines, and elemental sulfur toward 2-arylbenzothiazoles
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A relatively cheap copper salt-catalyzed, three-component approach providing 2-arylbenzothiazoles in good to excellent yields from readily available 2-iodoanilines, benzylamines, and sulfur powder is reported. This methodology allows preparation of various classes of 2-arylbenzothiazoles and provides a general, reliable approach.
- Wang, Rui,Ding, Yong-Liang,Liu, Hong,Peng, Shu,Ren, Jie,Li, Lei
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p. 945 - 949
(2015/02/19)
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- Copper-catalyzed multicomponent reactions of 2-iodoanilines, benzylamines, and elemental sulfur toward 2-arylbenzothiazoles
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A relatively cheap copper salt-catalyzed, three-component approach providing 2-arylbenzothiazoles in good to excellent yields from readily available 2-iodoanilines, benzylamines, and sulfur powder is reported. This methodology allows preparation of various classes of 2-arylbenzothiazoles and provides a general, reliable approach.
- Wang, Rui,Ding, Yong-Liang,Liu, Hong,Peng, Shu,Ren, Jie,Li, Lei
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p. 945 - 949
(2014/02/14)
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- KI-catalyzed arylation of benzothiazoles from the coupling of aryl aldehydes with benzothiazoles in neat water
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A KI-catalyzed oxidative coupling of benzothiazoles with aryl aldehydes has been developed using TBHP as an oxidant in neat water under metal free conditions. Various 2-aryl benzothiazoles were prepared in 36-79% yields for 28 examples. The mechanistic studies suggested that this transformation proceeded via a radical process. The Royal Society of Chemistry.
- Gao, Yuyu,Song, Qiuling,Cheng, Guolin,Cui, Xiuling
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supporting information
p. 1044 - 1047
(2014/02/14)
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- Copper-catalyzed synthesis of benzo[ b ]thiophenes and benzothiazoles using thiocarboxylic acids as a coupling partner
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An efficient copper-catalyzed approach to benzo[b]thiophene and benzothiazole derivatives using thiocarboxylic acids as a sulfur source has been developed. In the presence of CuI and 1,10-phen, and n-Pr3N as the base, (2-iodobenzyl)triphenylphosphonium bromide and (2-iodophenylimino) triphenylphosphorane reacted smoothly with thiocarboxylic acids to give benzo[b]thiophene and benzothiazole derivatives in good yields via sequential Ullmann-type C-S bond coupling and Wittig condensation.
- Yu, Hui,Zhang, Meishu,Li, Yuzhe
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p. 8898 - 8903
(2013/09/24)
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- Design, synthesis and structure-activity relationship of rhenium 2-arylbenzothiazoles as β-amyloid plaque binding agents
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To continue our efforts toward the development of 99mTc PiB analogs, we have synthesized 24 neutral and lipophilic Re (as a surrogate of 99mTc) 2-arylbenzothiazoles, and explored their structure-activity relationship for binding to Aβ1-40 fibrils. These Re complexes were designed and synthesized via the integrated approach, so their 99mTc analogs would have a greater chance of crossing the blood-brain barrier. While the lipophilicities (log PC18 = 1.59-3.53) of these Re 2-arylbenzothiazoles were all within suitable range, their binding affinities (Ki = 30-617 nM) to Aβ1-40 fibrils varied widely depending on the selection and integration of the tetradentate chelator into the 2-phenylbenzothiazole pharmacophore. For potential clinical applications, further refinement to obtain Re 2-arylbenzothiazoles with better binding affinities (99mTc analogs for more widespread application via the use of SPECT scanners.
- Pan, Jinhe,Mason, Neale S.,Debnath, Manik L.,Mathis, Chester A.,Klunk, William E.,Lin, Kuo-Shyan
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p. 1720 - 1726
(2013/04/10)
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- Iron-catalyzed arylation of benzoazoles with aromatic aldehydes using oxygen as oxidant
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An iron-catalyzed arylation of azoles with aromatic aldehydes using oxygen as oxidant has been discovered. The reaction proceeded well for a range of different substrates under oxidative conditions. The Royal Society of Chemistry.
- Liu, Saiwen,Chen, Ru,Guo, Xiangyu,Yang, Huiqiong,Deng, Guojun,Li, Chao-Jun
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supporting information
p. 1577 - 1580
(2013/02/22)
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- Palladium-catalyzed C-H cyclization in water: A milder route to 2-arylbenzothiazoles
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Water was successfully employed as a reaction medium in palladium-catalyzed C-H cyclization of thiobenzanilides. Reactions efficiently proceeded under considerably mild conditions such as 40 °C in water, providing a more practical, greener method for the synthesis of 2-arylbenzothiazoles. For some substrates, the addition of an amphiphilic surfactant greatly enhanced the process. The method represents a rare example of palladium-catalyzed C-H functionalization processes performed in water. Georg Thieme Verlag Stuttgart · New York.
- Inamoto, Kiyofumi,Nozawa, Kanako,Kondo, Yoshinori
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p. 1678 - 1682
(2012/07/17)
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- Fe-catalysed oxidative C-H functionalization/C-S bond formation
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Iron was used as the catalyst for the direct C-H functionalization/C-S bond formation under mild conditions. Various substrates could afford benzothiazoles in moderate to excellent yields. Preliminary mechanistic studies revealed that pyridine played a crucial role for the high yields and selectivities.
- Wang, Haibo,Wang, Lu,Shang, Jinsai,Li, Xing,Wang, Haoyuan,Gui, Jie,Lei, Aiwen
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supporting information; experimental part
p. 76 - 78
(2012/01/05)
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- Use of molecular oxygen as a reoxidant in the synthesis of 2-substituted benzothiazoles via palladium-catalyzed C-H functionalization/intramolecular C-S bond formation
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Molecular oxygen (O2) was successfully employed as a reoxidant in cyclizations of thiobenzanilides 1a-s through a palladium-catalyzed C-H functionalization/intramolecular C-S bond formation process, leading to an efficient, green method for the synthesis of 2-arylbenzothiazoles 2a-s. Addition of cesium fluoride (CsF) greatly enhanced the reactions, which produced variously substituted 2-arylbenzothiazoles with good functional group tolerance. Thioureas 4a-j were also found to be suitable substrates for the cyclization process using a palladium/O2 catalyst system, thus generating 2-aminobenzothiazoles 5a-j. One-pot syntheses of 2-aminobenzothiazoles 5a-j from aryl isothiocyanates 6 and amines 7 were also successful.
- Inamoto, Kiyofumi,Hasegawa, Chisa,Kawasaki, Junpei,Hiroya, Kou,Doi, Takayuki
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experimental part
p. 2643 - 2655
(2010/12/25)
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- Palladium-catalyzed synthesis of 2-substituted benzothiazoles via a C-H functionalization/intramolecular C-S bond formation process
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(Chemical Equation Presented) Catalytic synthesis of 2-substituted benzothiazoles from thiobenzanilides was achieved in the presence of a palladium catalyst through C-H functionalization/C-S bond formation. This method features the use of a novel catalytic system consisting of 10 mol % of Pd(II), 50 mol % of Cu(I), and 2 equiv of Bu4NBr that produced variously substituted benzothiazoles in high yields with good functional group tolerance.
- Inamoto, Kiyofumi,Hasegawa, Chisa,Hiroya, Kou,Doi, Takayuki
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supporting information; experimental part
p. 5147 - 5150
(2009/05/30)
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- Novel anti-inflammatory and analgesic heterocyclic amidines that inhibit nitrogen oxide (NO) production
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Heterocyclic amidines with anti-inflammatory and analgesic activity that inhibit nitrogen oxide production, of formula (I): in which:G1 and G2 are hydrogen, halogen, hydroxyl, C1-C4 alkoxy, C1-C4 alkyl, and an amidino substituent of formula Q, provided that, for each compound of formula (I), only one of the two substituents G1 or G2 is an amidino substituent of formula Q: and in which the substituents W, Y and X are combined to form 9- or 10-membered bicyclic heteroaromatic derivatives containing up to 2 hetero atoms in the same ring; andZ is an aryl or heteroaryl group, a linear or branched C1-C6 alkyl or alkenyl chain, a C1-C4 alkyl-aryl group or a C1-C4 alkyl-heteroaryl group.
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Page/Page column 20
(2010/02/13)
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- Novel anti-inflammatory and analgesic heterocyclic amidines that inhibit nitrogen oxide (NO) production
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Heterocyclic amidines with anti-inflammatory and analgesic activity that inhibit nitrogen oxide production, of formula (I): in which: G1 and G2 are hydrogen, halogen, hydroxyl, C1-C4 alkoxy, C1-C4 alkyl, and an amidino substituent of formula Q, provided that, for each compound of formula (I), only one of the two substituents G1 or G2 is an amidino substituent of formula Q: and in which the substituents W, Y and X are combined to form 9- or 10-membered bicyclic heteroaromatic derivatives containing up to 2 hetero atoms in the same ring; and Z is an aryl or heteroaryl group, a linear or branched C1-C6 alkyl or alkenyl chain, a C1-C4 alkyl-aryl group or a C1-C4 alkyl-heteroaryl group.
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Page/Page column 14
(2010/02/13)
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- 4,5-azolo-oxindoles
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Disclosed are novel 4,5-azolo-oxindoles having the formula These compounds inhibit cyclin-dependent kinases (CDKs), in particular CDK2. Thus, these compounds and their pharmaceutically acceptable salts, and prodrugs of said compounds, are anti-proliferative agents useful in the treatment or control of cell proliferative disorders, in particular cancer. Also disclosed are pharmaceutical compositions containing these compounds, and methods for the treatment and/or prevention of cancer, particularly in the treatment or control of solid tumors using these compounds, as well as intermediates useful in the preparation of compounds of formula I.
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