- Metal-free C–H mercaptalization of benzothiazoles and benzoxazoles using 1,3-propanedithiol as thiol source
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A facile and effective C–H functionalization strategy for the synthesis of 2-mercaptobenzothiazoles and 2-mercaptobenzoxazoles is described. 1,3-Propanedithiol was employed to convert benzothiazoles and benzoxazoles to the corresponding heteroarylthiols in the presence of potassium hydroxide and DMSO. This novel protocol is featured by direct C–H mercaptalization of heteroarenes and a simple reaction system.
- Xiao, Yan,Jing, Bing,Liu, Xiaoxia,Xue, Hongyu,Liu, Yajun
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supporting information
p. 279 - 284
(2019/02/20)
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- Water-Promoted Chlorination of 2-Mercaptobenzothiazoles
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Substituted benzothiazoles play an important role in medicinal chemistry due to their pharmacological properties. Their 2-substituted derivatives are often prepared from 2-chlorobenzothiazoles, which in turn can be synthesized from the 2-mercapto precursor using sulfuryl chloride. In practice, this seemingly straightforward and widely used reaction can be impeded by poor reproducibility and low reaction yields. In this communication, we report that the simple addition of water to the reaction leads to remarkable improvements in reaction efficiency. We attribute this effect to the formation of acid through partial hydrolysis of sulfuryl chloride. This hypothesis is supported by the observation that improved yields were also obtained in the presence of some anhydrous acidic additives. The simple combination of sulfuryl chloride and water reproducibly provides excellent yields for a range of chlorinated products.
- Wimmer, Laurin,Parmentier, Michael,Riss, Bernard,Kapferer, Tobias,Ye, Chao,Li, Lei,Kim, Hongyong,Li, Jialiang
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p. 2027 - 2032
(2018/04/16)
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- Highly efficient synthesis of 2-mercaptobenzothiazole derivatives in water: Metal sulfide-disulfide dynamic interchange reaction
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A convenient and efficient method for the synthesis of 2-mercaptobenzothiazoles from disulfide and CS2 mediated by a metal sulfide in water is described. This synthetic methodology could be used to prepare diverse 2-mercaptobenzothiazole derivatives in good to excellent yields. In this paper, the concept of metal sulfide-disulfide dynamic interchange reaction was put forward. Then the intermediates of the interchange reaction between NaHS and a disulfide were detected by LC-MS, which demonstrated that the S-S bond of the disulfide could be broken by the metal sulfide through the dynamic interchange reaction. In addition, NaHS was eventually transformed into sulfur S8 by the dynamic interchange reaction. Moreover, the underlying mechanism of 2-mercaptobenzothiazole formation is proposed, in which NaHS not only acts as an S-S bond cleaving agent but also as an activator of CS2. As a result, a novel synthetic route for the preparation of sulfur-containing heterocycles from a disulfide is developed.
- Lou, Chunqing,Zhu, Ning,Fan, Ronghua,Hong, Hailong,Han, Limin,Zhang, Jianbin,Suo, Quanling
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p. 1102 - 1108
(2017/08/15)
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- A α 7 smoke alkali acetylcholine receptor ligand and its preparation method
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The present invention relates to an alpha7 nicotinic acetylcholine receptor ligand and a preparation method thereof. The ligand includes an agonist and an imaging agent, the agonist is a 1,4-diazabicyclo [3.2.2] nonane-benzo heterocyclic derivative, and the imaging agent is 125I and 18F-trifluoromethyl marker. The derivatives both have good brain uptake, the absorption values in different regions of the brain are basally consistent with the distribution of alpha7nAChR receptors, the uptake of the derives is highest in hippocampus, thalamus, cortex and other regions where the alpha7nAChR receptors targetedly distribute, and the derives can be blocked by known alpha7nAChR ligands but can not be blocked by alpha4beta2 medicine. Therefore, the 1,4-diazabicyclo [3.2.2] nonane-benzo heterocyclic derivative and the 125I and 18F-trifluoromethyl marker are potential agonist and imaging agent for alpha7 nicotinic acetylcholine receptors.
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Paragraph 0028-0030
(2018/03/24)
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- Green synthesis method of 2-mercaptobenzothiazoles derivatives
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The invention provides a green synthesis method of 2-mercaptobenzothiazoles derivatives. The method comprises the step of enabling o-amino aromatic disulfide, CS2 and metal sulfide to be in contact with a solvent to obtain the 2-mercaptobenzothiazoles derivatives, wherein the solvent is at least one of water, low carbon alcohol, dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), N-methyl pyrrolidone (NMP) and 1, 4-dioxane. Compared with the prior art, the method enables the o-amino aromatic disulfide to react with the CS2, thus rapidly and efficiently synthesizing the 2-mercaptobenzothiazoles derivatives; the raw materials used by the method are stable, easy to obtain and low in cost; the synthesis method is simple and convenient in operation, short in step, high in yield and easy in purification of a product.
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Paragraph 0068; 0069
(2018/02/04)
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- An efficient copper-catalyzed synthesis of 2-mercaptobenzothiazole through S-arylation/heterocyclization of 2-haloaniline with potassium xanthate
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A mild and efficient methodology to produce 2-mercaptobenzothiazoles in DMF via ortho-haloaniline coupling with potassium O-ethyl dithiocarbonate catalyzed by copper without a ligand has been developed.
- Liu, Lei,Zhu, Ning,Gao, Min,Zhao, Xiaole,Han, Limin,Hong, Hailong
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p. 699 - 701
(2016/05/09)
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- Efficient, Iron-Catalyzed Synthesis of 2-Mercaptobenzothiazole Through S-Arylation/Heterocyclization of 2-Haloaniline with Potassium Xanthate
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A mild and practical method for the synthesis of 2-mercaptobenzothiazole has been developed by using iron as an efficient catalyst. The present tandem reaction process allows access to a wide range of 2-mercaptobenzothiazoles in good to excellent yields by the reaction of 2-haloaniline with potassium O-ethyl dithiocarbonate in the presence of FeF3 as a catalyst and 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl as a ligand under an atmosphere of argon.
- Gao, Min,Lou, Chunqing,Zhu, Ning,Qin, Weijing,Suo, Quanling,Han, Limin,Hong, Hailong
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supporting information
p. 2378 - 2385
(2015/10/12)
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- Copper-Catalyzed Three-Component Synthesis of Benzothiazolethiones from o-Iodoanilines, Isocyanide, and Potassium Sulfide
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An efficient copper catalyzed strategy for the synthesis of a variety of benzothiazolethione derivatives has been developed. In the presence of CuCl, the three-component reaction of o-iodoanilines and K2S with p-toluenesulfonylmethyl isocyanide proceeded smoothly to obtain the corresponding benzothiazolethiones in good to excellent isolated yields. Notably, isocyanide functioned as a carbon source and K2S functioned as a sulfur source in this reaction.
- Dang, Pan,Zeng, Weilan,Liang, Yun
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supporting information
p. 34 - 37
(2015/07/28)
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- DERIVATIVES OF HETEROARYLSULFONAMIDES, THEIR PREPARATION AND THEIR APPLICATION IN HUMAN THERAPY
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The present invention concerns derivatives of heteroarylsulfonamides, notably as blockers of Kv potassium channels, and more particularly of channels Kv1.5, Kv4.3 or Kv11.1, their application in clinical therapy and their preparation methods. These compounds correspond to the following general formula (I): where R1 represents one or more substituents of the phenyl core X such as: hydrogen, halogen, trifluoromethyl, trifluoromethoxy, linear or branched C1-C4 alkyl, or linear or branched C1-C4 alkoxy, A represents oxygen or sulphur, B represents nitrogen when n=1 or 2 and D represents —C(═O)—, or B represents CH when n=0 and D represents —CH2O— or when n=1 and D represents —O—, R2 represents a hydrogen, a methyl, a fluorine or chlorine atom or a methoxy, HetAr represents a pyridyl or quinolyl group, possibly substituted by a group such as a linear or branched C1-C4 alkyl, a linear or branched C1-C4 alkoxy, a halogen, or a trifluoromethyl, and to their pharmaceutically acceptable salts.
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Paragraph 0067; 0068; 0075; 0076
(2013/07/19)
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- DERIVATIVES OF HETEROARYLSULFONAMIDES, THEIR PREPARATION AND THEIR APPLICATION IN HUMAN THERAPY
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The present invention concerns derivatives of heteroarylsulfonamides, notably as blockers of Kv potassium channels, and more particularly of channels Kv1.5, Kv4.3 or Kv11.1, their application in clinical therapy and their preparation methods. These compounds correspond to the following general formula (I): where R1 represents one or more substituents of the phenyl core X such as: hydrogen, halogen, trifluoromethyl, trifluoromethoxy, linear or branched C1-C4 alkyl, or linear or branched C1-C4 alkoxy, A represents oxygen or sulphur, B represents nitrogen when n=1 or 2 and D represents ?C(=O)-, or B represents CH when n=0 and D represents ?CH2O? or when n=1 and D represents ?O?, R2 represents a hydrogen, a methyl, a fluorine or chlorine atom or a methoxy, HetAr represents a pyridyl or quinolyl group, possibly substituted by a group such as a linear or branched C1-C4 alkyl, a linear or branched C1-C4 alkoxy, a halogen, or a trifluoromethyl, and to their pharmaceutically acceptable salts.
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Page/Page column 18
(2012/06/15)
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- A convenient metal-free method for the synthesis of benzothiazolethiones from o-haloanilines and carbon disulfide
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A convenient method has been developed for the preparation of a variety of 1,3-benzothiazole-2(3H)-thiones. The reaction proceeds from an o-haloaniline derivative and carbon disulfide in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene at 80-140 °C to g
- Wang, Fei,Xi, Chanjuan,Zhao, Peng
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p. 1477 - 1480
(2020/01/03)
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- Synthesis of 2-mercaptobenzothiazoles via DBU-promoted tandem reaction of o-haloanilines and carbon disulfide
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An efficient strategy for the synthesis of a variety of 2-mercaptobenzothiazole derivatives has been developed. The reaction proceeded from o-haloaniline derivatives and carbon disulfide via a tandem reaction in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to afford the corresponding 2-mercaptobenzothiazole derivatives in good to excellent yields.
- Wang, Fei,Cai, Shangjun,Wang, Zhipeng,Xi, Chanjuan
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supporting information; experimental part
p. 3202 - 3205
(2011/08/07)
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- Improved synthesis of 2-(3H)benzothiazolethiones under microwave irradiation
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2-(3H)Benzothiazolethiones (2-mercaptobenzothiazole) are prepared by an improved method, which utilizes microwave-assisted cyclization of the corresponding ortho-haloanlines with potassium O-ethyl dithiocarbonate. By using microwave irradiation, the relative reactivity of 2-chloroanilines was greatly improved to the same level as that of 2-fluoroanilines and 2-bromoanilines. Copyright Taylor & Francis Group, LLC.
- Huang, Wei,Tan, Ying,Ding, Ming-Wu,Yang, Guang-Fu
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p. 369 - 376
(2007/10/03)
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- A convenient synthesis of 2-mercapto and 2-chlorobenzothiazoles
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A convenient synthesis of 2-mercapto and 2-chlorobenzothiazoles is described. The key feature of the synthesis is an exclusive ortho-selective nucleophilic aromatic substitution reaction of ortho-haloanilines with potassium/sodium O-ethyl dithiocarbonate under mild conditions. Subsequent intra-molecular cyclization affords 2-mercaptobenzothiazoles in high yields. The 2-mercaptobenzothiazoles are readily converted to corresponding 2-chlorobenzothiazoles upon treatment with sulfuryl chloride.
- Zhu, Lei,Zhang, Mingbao,Dai, Miao
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p. 727 - 730
(2007/10/03)
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- Process for the preparation of 2-mercaptobenzothiazoles
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The preparation of (optionally substituted) 2-mercaptobenzothiazole by reaction of corresponding 2-halogenoanilines with an alkali metal xanthate or alkaline earth metal xanthate or with CS2 in the presence of bases.
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