92161-46-1

Upstream product

• 123-11-5 4-methoxy-benzaldehyde 
• 1004-00-8 4-chloro-2-aminobenzenethiol 
• 119-52-8 4,4'-dimethoxybenzoin 
• 105-13-5 4-Methoxybenzyl alcohol 
• 100-06-1 1-(4-methoxyphenyl)ethanone 
• 874-90-8 4-methoxybenzonitrile 
• 7099-91-4 p-methoxybenzoylformic acid 
• 29124-55-8 2-amino-4-chlorophenyl disulfide 
• 155164-68-4 4,5-Dichloro-2-(4-methoxy-benzoyl)-2H-pyridazin-3-one 
• 6828-35-9 5-chloro-2-iodoaniline 
• 108-42-9 3-chloro-aniline 
• 100-07-2 4-methoxy-benzoyl chloride 
• 7465-93-2 N-(3-chlorophenyl)-4-methoxybenzamide 
• 1312920-16-3 N-(3-chlorophenyl)-4-methoxybenzenecarbothioamide 

Downstream Products

• 91692-73-8 2-(4-chloro-phenyl)-benzothiazol-6-ol 
• 96367-61-2 {2-[2-(4-chloro-phenyl)-benzothiazol-6-yloxy]-ethyl}-diethyl-amine 

Relevant academic research and scientific papers

Ionic-Liquid-Catalyzed Synthesis of Imines, Benzimidazoles, Benzothiazoles, Quinoxalines and Quinolines through C?N, C?S, and C?C Bond Formation

We report the tetramethyl ammonium hydroxide catalyzed oxidative coupling of amines and alcohols for the synthesis of imines under metal-free conditions by utilizing oxygen from air as the terminal oxidant. Under the same conditions, with ortho-phenylene diamines and 2-aminobenzenethiols the corresponding benzimidazoles and benzothiazoles were obtained. Quinoxalines were obtained from ortho-phenylene diamines and 1-phenylethane-1,2-diol, the conditions were then extended to the synthesis of quinoline building blocks by reaction of 2-amino benzyl alcohols either with 1-phenylethan-1-ol or acetophenone derivatives. The formation of C?N, C?S and C?C bonds was achieved under metal-free conditions. A broad range of amines (aromatic, aliphatic, cyclic and heteroaromatic) as well as benzylic alcohols including heteroaryl alcohols reacted smoothly and provided the desired products. The mild reaction conditions, commercially available catalyst, metal-free, good functional-group tolerance, broad range of products (imines, benzimidazoles, benzothiazoles, quinoxalines and quinolines) and applicability at gram scale reactions are the advantages of the present strategy.

Oxidant/Solvent-Controlled I2-Catalyzed Domino Annulation for Selective Synthesis of 2-Aroylbenzothiazoles and 2-Arylbenzothiazoles under Metal-Free Conditions

A simple and practical domino protocol for the selective synthesis of 2-aroylbenzothiazoles and 2-aryl benzothiazoles catalyzed by I2 is developed under metal-free conditions. The reaction outcomes are exclusively controlled by the reaction oxidant/medium. With DMSO employed as both the solvent and the oxidant, an oxidation of aromatic methyl ketones takes precedence over the condensation with 2-aminobenzenethiols. On the other hand, when the reaction was carried out in PhNO2 or in 1,4-dioxane containing PhNO2, the condensation of aromatic methyl ketones with 2-aminobenzenethiols has priority to form imines which is followed by an oxidation of the methyl group from ketones to afford 2-arylbenzothiazoles as a sole product. The PhNO2/I2 co-catalytic system is proposed first time.

Urea nitrate–catalyzed C-N and C-S bond formation: A mechanochemical approach for 5-chloro-2-arylbenzo[d]thiazole derivatives

A series of substituted 5-chloro-2-arylbenzo[d]thiazoles were synthesized using 4-chloro-2-aminothiophenol and aromatic aldehydes in the presence of urea nitrate as a catalyst using the mechanochemical grindstone technique. This protocol was effectively carried out under metal-free conditions at room temperature, and the desired products were obtained in high to excellent yields in short reaction time (30–60 s). The structure of all the synthesized derivatives was confirmed by spectral characterization. The designed protocol has several benefits like eco-friendly, solvent-free, high yields, easy workup, and recyclability of catalyst. The catalyst was reusable at least four times without significant loss of activity. The good functional group tolerance with a series of derivatives has been demonstrated.

Synthesis of benzothiazoles using fluorescein as an efficient photocatalyst under visible light

This work reports a novel and efficient method for the synthesis of benzothiazoles using 2-aminothiophenol derivatives in conjunction with aromatic aldehyde as starting materials via visible-light-induced condensation cyclization. Utilizing fluorescein as the photocatalyst and blue LED lamp as the light source, the reaction proceeds in the presence of a molecular oxygen atmosphere without the need for metal catalyst or an additional oxidant. Significantly, this method exhibits good tolerance in substrates, and a variety of 2-aminothiophenol derivatives and aromatic aldehyde are amenable to producing the corresponding benzothiazoles in high to excellent yields.

Synthesis of Benzothiazoles via Photooxidative Decarboxylation of α-Keto Acids

Herein, synthesis of benzothiazoles via decarboxylative cross-coupling between α-keto acids and 2-aminothiophenols under blue LED irradiation without using any photocatalyst or metal at room temperature is described. The formation of benzothiazole is driven by the EDA (electron donor-acceptor) complex formed between α-keto acid and 2-aminothiophenol. This methodology gives easy access to 2-substituted and -unsubstituted benzothiazoles in moderate to good yields. α-Keto acids and 2-aminothiophenols bearing different functional groups were easily transformed under the given conditions. (Figure presented.).

Synthesis of 2-substituted benzothiazoles via the Br?nsted acid catalyzed cyclization of 2-amino thiophenols with nitriles

A convenient and efficient method for the synthesis of 2-substituted benzothiazoles from simple and readily available 2-amino thiophenols and nitriles is described. The Br?nsted acid-catalyzed cyclization reaction was performed under metal and solvent-free conditions.

Synthesis, and In Vitro and In Silico α-Glucosidase Inhibitory Studies of 5-Chloro-2-Aryl Benzo[d]thiazoles

Twenty-five derivatives of 5-chloro-2-aryl benzo[d]thiazole (1–25) were synthesized and evaluated for their α-glucosidase (S. cerevisiae EC 3.2.1.20) inhibitory activity in vitro. Among them eight compounds showed potent activity with IC50 values between 22.1 ± 0.9 and 136.2 ± 5.7 μM, when compared with standard acarbose (IC50 = 840 ± 1.73 μM). The most potent compounds 4, 9, and 10 showed IC50 values in the range of 22.1 ± 0.9 to 25.6 ± 1.5 μM. Compounds 2, 5, 11, and 19 showed IC50 values within the range of 40.2 ± 0.5 to 60.9 ± 2.0 μM. Compounds 1 and 3 were also found to be good inhibitors with IC50 values 136.2 ± 5.7 and 104.8 ± 9.9 μM, respectively. Their activities were compared with α-glucosidase inhibitor drug acarbose (standard) (IC50 = 840 ± 1.73 μM). The remaining compounds were inactive. Structure-activity relationships (SAR) have also been established. Kinetics studies indicated compounds 2, 3, 10, 19, and 25 to be non-competitive, while 1, 5, 9, and 11 as competitive inhibitors of α-glucosidase enzyme. All the active compounds (1–5, 9–11, and 19) were also found to be non-cytotoxic, in comparison to the standard drug i.e., doxorubicin (IC50 = 0.80 ± 0.12 μM) in MTT assay. Furthermore, molecular interactions of active compounds with the enzyme binding sites were predicted through molecular modeling studies.

α-Keto Acids as Acylating Agents in the Synthesis of 2-Substituted Benzothiazoles and Benzoselenazoles

Herein, we report the first decarboxylative oxidation of α-keto acids that is promoted by sodium metabisulfite (Na2S2O5) to obtain 2-substituted benzothiazoles and benzoselenazoles. Diaryl disulfides and diselenides were used as chalcogen sources, and the desired products were obtained in moderate to excellent yields. This protocol does not require an inert gas, transition metals, or harsh reaction conditions, and CO2 is released as an environmentally benign coproduct. The presence of Na2S2O5 was essential to guarantee that the reaction reached completion and afforded maximum product yields.

Niobium-promoted reaction of α-phenylglyoxylic acid with ortho-functionalized anilines: Synthesis of 2-arylbenzothiazoles and 3-aryl-2H-benzo[b][1,4]benzoxazin-2-ones

A new and general method to prepare 2-arylbenzothiazoles and 3-aryl-2H-benzo[b][1,4]benzoxazin-2-ones by the reaction of α-arylglyoxylic acid with o-aminothiophenol and o-aminophenol respectively is described. The use of ammonium niobium oxalate (ANO) as the catalyst and PEG-400 as the solvent were crucial to afford the title compounds in good yields and selectivity. The reaction time can be reduced from hours to few minutes when ultrasound is used as an alternative energy source.

A method for synthesis of benzothiazole derivatives (by machine translation)

The invention relates to a synthesis method of benzothiazole derivatives, which comprises the following step: in an organic solvent, reacting hydroxyketone compounds and 2-aminothiophenol in the presence of a catalyst and an optional accelerator to synthesize the benzothiazole derivatives. The method has the advantages of high yield, high purity, simple after-treatment and the like, provides a new route and method for synthesis of the benzothiazole derivatives, and has favorable potential applications and research value.