- Antioxidant and method for preparing antioxidant
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The invention discloses an antioxidant and a method for preparing the antioxidant. An intermediate 2 reacts with an intermediate 5 to obtain an intermediate 14, the intermediate 14 isoxidized with potassium permanganate, an esterification reaction is then carried out with an intermediate 13 to obtain an intermediate 15, the intermediate 15 is reduced with tin powder to obtain an intermediate 16, the intermediate 16 and the intermediate 8 are subjected to dehydration condensation, the antioxidant is prepared, the antioxidant contains a large number of sulfur atoms, the sulfur atoms can be oxidized to form sulfoxide and sulfone compounds, the antioxidant has good oxidation resistance, free radicals generated by macromolecules can be captured, then the free radical branching reaction is inhibited, and the antioxidant activity is improved. The oxidation resistance of the high-molecular material is improved, and the self relative molecular mass is large and is not easy to separate out from the high-molecular material.
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Paragraph 0011; 0046; 0048; 0054; 0056; 0062; 0064
(2021/08/06)
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- One-Pot Tandem Access to Phenothiazine Derivatives from Acetanilide and 2-Bromothiophenol via Rhodium-Catalyzed C-H Thiolation and Copper-Catalyzed C-N Amination
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A one-pot and step economic reaction involving Rh(III)-catalyzed C-H thiolation and relay Cu(II)-catalyzed C-N amination of acetanilide and 2-bromothiophenol is reported here, with several valuable phenothiazine products obtained. This synthesis protocol proceeds from easily starting materials, demonstrating high atom economy, broad substrate scope, and good yield. Furthermore, the directing group can be easily eliminated, and chlorpromazine is provided in a large scale; thus this synthesis protocol could be utilized to construct phenothiazine scaffolds.
- Rui, Xiyan,Wang, Chao,Si, Dongjuan,Hui, Xuechao,Li, Keting,Wen, Hongmei,Li, Wei,Liu, Jian
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p. 6622 - 6632
(2021/05/29)
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- Efficient and regioselective synthesis of phenothiazine via ferric citrate catalyzed C-S/C-N cross-coupling
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Efficient C-S and C-N cross-coupling reactions have been developed for regioselective, scalable and environmentally benign synthesis of substituted phenothiazine derivatives. Cross-coupling reactions were demonstrated on various challenging substrates using non-toxic, highly economical, readily available ferric citrate as a catalyst to get desired product with high regioselectivity. Atom economy is the added advantage of this protocol since additional N-protection step before coupling and eventual deprotection of the same to obtain the desired product arenot required. To the best of our knowledge, this is the first report on the use of inexpensive ferric citrate as a catalyst without involving any ligand for the synthesis of regioselectively substituted phenothiazine.
- Das, Tonmoy Chitta,Quadri, Syed Aziz Imam,Farooqui, Mazahar
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supporting information
p. 16 - 24
(2019/05/04)
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- Iron catalytic phenothiazine synthetic method of compound
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The invention provides a synthetic method of an iron-catalyzed phenothiazine compound. The synthetic method comprises the following step: in the presence of an iron salt catalyst, a ligand and an alkali, carrying out C-S coupling, C-N coupling and deacylation reaction on raw materials (N-(2-sulfydryl phenyl) acetamide and o-dibromobenzene) at a certain temperature to obtain the phenothiazine compound. The synthetic method provided by the invention is simple in operation, mild in condition, wide in application range, relatively high in yield and short in reaction time and has a good industrial prospect.
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Paragraph 0018; 0019; 0030; 0031
(2017/04/08)
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- Transition-metal-free synthesis of phenothiazines from S-2-acetamidophenyl ethanethioate and ortho-dihaloarenes
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An efficient cesium carbonate-mediated synthesis of phenothiazine derivatives from S-2-acetamidophenyl ethanethioates and ortho-dihaloarenes has been developed. This protocol affords an efficient approach for the construction of phenothiazine derivatives without the need of transition-metal catalyst or ligand. A plausible mechanism is proposed.
- Zhou, Yue,Zeng, Qingle,Zhang, Li
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supporting information
p. 710 - 715
(2017/03/27)
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- Radical Route to 1,4-Benzothiazine Derivatives from 2-Aminobenzenethiols and Ketones under Transition-Metal-Free Conditions
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Transition-metal-free radical access to 1,4-benzothiazine derivatives from o-aminobenzenethiols is disclosed. This procedure is available for various ketones including α,β-unsaturated, cyclic, linear, and fluoroalkyl ketones to generate a number of 1,4-benzothiazines, which exist in numerous bioactive and natural molecules, rendering this protocol attractive to both synthetic and medicinal chemistry.
- Lin, Ya-mei,Lu, Guo-ping,Wang, Rong-kang,Yi, Wen-bin
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supporting information
p. 6424 - 6427
(2016/12/23)
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- A method of synthesizing phenoxthine compounds
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The invention develops a method for synthesizing phenothiazine compounds by using benzothiazole and derivatives thereof as well as 1-bromo-2-iodobenzene and derivatives thereof as raw materials and copper or copper salt/N-alkoxy-1H-pyrrolic amide system as a copper catalyst. The method is a brand-new method for synthesizing phenothiazine compounds. The method has the characteristics of low temperature, short reaction time, low solvent toxicity and wide substrate adaptability, and has wide application prospects in the aspect of preparation of medicines, pesticides and materials.
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Paragraph 0028; 0029; 0030; 0031
(2016/10/17)
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- Copper-Catalyzed Domino Reactions for the Synthesis of Phenothiazines
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A method for the one-pot synthesis of phenothiazines from benzothiazoles and aryl ortho-dihalides was explored. Preliminary work on the mechanism of the reaction suggested that it follows a domino process, including the hydrolysis of benzothiazoles followed by C-S coupling and C-N coupling. The low loading of the catalyst system (5 mol-% for both copper and ligand), the mild experimental conditions (90 °C, 12 h), and the use of a green reaction medium make this synthesis very attractive to academia and industry. A copper-catalyzed domino reaction consisting of the hydrolysis of benzothiazoles followed by C-S and C-N couplings for the synthesis of phenothiazines from benzothiazoles and aryl ortho-dihalides is described. The low loading of the catalyst system, mild experimental conditions, and the use of polyethylene glycol as the solvent make this synthetic approach very attractive to academia and industry.
- Huang, Manna,Huang, Dongting,Zhu, Xinhai,Wan, Yiqian
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supporting information
p. 4835 - 4839
(2015/08/03)
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- Method for the Synthesis of Phenothiazines via a Domino Iron-Catalyzed C-S/C-N Cross-Coupling Reaction
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An environmentally benign and efficient method has been developed for the synthesis of phenothiazines via a tandem iron-catalyzed C-S/C-N cross-coupling reaction. Some of the issues typically encountered during the synthesis of phenothiazines in the presence of palladium and copper catalysts, including poor substrate scope, long reaction times and poor regioselectivity, have been addressed using this newly developed iron-catalyzed method.
- Hu, Weiye,Zhang, Songlin
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p. 6128 - 6132
(2015/06/30)
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- A catalyst system, copper/ N -methoxy-1 H -pyrrole-2-carboxamide, for the synthesis of phenothiazines in poly(ethylene glycol)
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A copper/N-methoxy-1H-pyrrole-2-carboxamide catalyst system has been established for the preparation of phenothiazines in good yields by two routes, starting from 2-iodoanilines and 2-bromobenzenethiol and from aryl ortho-dihalides and o-aminobenzenethiols, by conducting the reaction at 90 °C in poly(ethylene glycol)-100 (PEG-100). In addition, the catalyst system was useful for promoting direct arylation of various aryl amines, aliphatic amines, and aqueous ammonia. The simple experimental operation, low loading of catalyst system together with the use of green solvent, makes it attractive for the versatile syntheses of phenothiazines and various amines.
- Huang, Manna,Hou, Jianying,Yang, Ruiqiao,Zhang, Liting,Zhu, Xinhai,Wan, Yiqian
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supporting information
p. 3356 - 3364
(2015/02/02)
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- A facile synthesis of pechmann dyes
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A facile synthesis of Pechmann dyes has been accomplished by the reaction of substituted N-phenacyl-4-dimethylaminopyridinium halides with dimethyl maleate in the presence of DBU. Based on a related 4-DMAP elimination product and an isolated monolactone intermediate a reaction mechanism has been proposed. The scope of this synthetic method is determined by the availability of α-haloaroyl or heteroaroyl derivatives. DBU=1,8-diazabicycloundec-7-ene, DMAP=4-dimethylaminopyridine. A facile synthesis of Pechmann dyes has been accomplished by the reaction of substituted N-phenacyl-4-dimethylaminopyridinium halides with dimethyl maleate in the presence of DBU (see scheme). Based on a related 4-DMAP elimination product and an isolated monolactone intermediate a reaction mechanism has been proposed. The scope of this synthetic method is determined by the availability of α-haloaroyl or heteroaroyl derivatives. DBU=1,8-diazabicycloundec-7-ene, DMAP=4-dimethylaminopyridine.
- Hopf, Henning,Jones, Peter G.,Nicolescu, Alina,Bicu, Elena,Birsa, Lucian M.,Belei, Dalila
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supporting information
p. 5565 - 5568
(2014/05/20)
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- Synthesis of phenothiazines from cyclohexanones and 2-aminobenzenethiols under transition-metal-free conditions
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A convenient method for the synthesis of various substituted phenothiazines from cyclohexanones and 2-aminobenzenethiols using molecular oxygen as hydrogen acceptor in the absence of transition-metals is described. For the first time cyclohexanones were used as coupling partners for the construction of phenothiazines.
- Liao, Yunfeng,Jiang, Pengcheng,Chen, Shanping,Xiao, Fuhong,Deng, Guo-Jun
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p. 18605 - 18608
(2013/10/21)
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- Synthesis of phenothiazines via ligand-free CuI-catalyzed cascade C-S and C-N coupling of aryl ortho-dihalides and ortho-aminobenzenethiols
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A ligand-free CuI-catalyzed cascade C-S and C-N cross coupling of (hetero)aryl ortho-dihalides and ortho-aminobenzenethiols has been developed, and various phenothiazines were synthesized with excellent regioselectivity. A possible mechanism is proposed for the cascade coupling.
- Dai, Chuan,Sun, Xiaofei,Tu, Xingzhao,Wu, Li,Zhan, Dan,Zeng, Qingle
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experimental part
p. 5367 - 5369
(2012/06/04)
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- Assembly of substituted phenothiazines by a sequentially controlled CuI/L-proline-catalyzed cascade C-S and C-N bond formation
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(Chemical equation presented) In the pro-line of fire: A general and efficient cascade reaction approach to substituted phenothiazines, which relies on controlled sequential Cul/L-prolinecatalyzed C-S and C-N bond formations, is described. DMSO = dimethylsulfoxide.
- Dawei, Ma.,Geng, Qian,Zhang, Hui,Jiang, Yongwen
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supporting information; experimental part
p. 1291 - 1294
(2010/05/17)
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- The singlet oxygen oxidation of chlorpromazine and some phenothiazine derivatives. Products and reaction mechanisms
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(Chemical Equation Presented) A kinetic and product study of the reactions of chlorpromazine 1, N-methylphenothiazine 2, and N-ethylphenothiazine 3 with singlet oxygen was carried out in MeOH and MeCN. 1 undergoes exclusive side-chain cleavage, whereas the reactions of 2 and 3, in MeOH, afforded only the corresponding sulfoxides. A mechanism for the reaction of 1 is proposed where the first step involves an interaction between singlet oxygen and the side-chain dimethylamino nitrogen. This explains why no side-chain cleavage is observed for 2 and 3.
- Baciocchi, Enrico,Del Giacco, Tiziana,Lanzalunga, Osvaldo,Lapi, Andrea,Raponi, Daniele
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p. 5912 - 5915
(2008/02/10)
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- Structures and dynamics of the lowest excited triplet states and cation radicals of phenothiazine and 2-chlorophenothiazine: Transient resonance Raman and absorption study
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Transient resonance Raman and absorption spectra of the lowest excited triplet states T1 and the cation radicals of phenothiazine and 2-chlorophenothiazine were measured. It was found that in the photoreaction of 2-chlorophenothiazine a transient exhibiting an absorption band at 556 nm was generated from the cation radical. The corresponding transient was not observed in the absorption spectrum of phenothiazine, a fact which suggests a possibility of phenothlazinyl radical generation for 2-chlorophenothiazine by photoinduced dechlorination. Vibrational assignments of the T1 states and the cation radicals of the both compounds were made based on the frequency shifts on isotopic substitutions. Unusually large low-frequency shifts of the phenyl 8a and 8b modes were observed in the T1 state but no appreciable shifts were detected in the cation radical, indicating that the phenyl rings are drastically weakened, and therefore, the phenyl C-C bonds are very much lengthened in the T1 state. This implies that the excitation is strongly localized on the phenyl rings and the T1 state has an n-π* character.
- Sarata, Gaku,Noda, Yoshihiro,Sakai, Makoto,Takahashi, Hiroaki
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- Ozonization of phenothiazine and its analogues
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When phenothiazine and phenoxazine were ozonized in dichloromethane, the cation radicals and the ozonate anion radicals were detected, whereas, in the ozonization of phenoxathiin and thianthrene, these radicals were not observed. Formation of these radicals was more favorable as greater was the polarity of the solvent and lower was the oxidation potential of the substrate. Ozonization of phenothiazine and phenoxazine in polar solvents was explained by the electron-transfer mechanism accompanied by the electrophilic ozone attack, and that of phenoxathiin and thianthrene by the electrophilic ozone attack alone.
- Matsui,Miyamoto,Shibata,Takase
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p. 2526 - 2530
(2007/10/02)
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