137-07-5Relevant articles and documents
Synthesis of 2H-1,4-benzothiazin-3(4H)-ones and 2H-1,4-benzoselenazin-3(4H)-ones with the aid of samarium(II) iodide
Zhong, Weihui,Zhang, Yongmin
, p. 3125 - 3127 (2001)
Bis(o-nitrophenyl) disulfides or diselenides were easy to reduce by samarium(II) iodide to produce the active intermediates 2 in situ, which readily react with α-halocarboxylic derivatives to yield the corresponding products 2H-1,4-benzothiazin-3(4H)-ones and 2H-1,4-benzoselenazin-3(4H)-ones, respectively, in moderate to high yields under mild conditions.
Iodine mediated oxidative cross-coupling of unprotected anilines and heteroarylation of benzothiazoles with 2-methylquinoline
Rahim, Abdul,Shaik, Siddiq Pasha,Baig, Mirza Feroz,Alarifi, Abdullah,Kamal, Ahmed
, p. 635 - 644 (2018)
Iodine-promoted oxidative C-H/C-H cross-coupling of unprotected anilines and 2-methylquinoline to furnish C4-carbonylated aniline (4-aminophenyl)(quinoline-2-yl) methanones in moderate to good yields has been demonstrated. This work provides the first site-selective approach for the synthesis of free amino groups containing methanones including unprecedented C-H functionalization rather than the N-H functionalization of unprotected anilines via the Kornblum oxidation of 2-methylquinoline. Furthermore, we noticed that the incorporation of KOH under standard conditions provides 2-heteroarylbenzothiazoles from benzothiazoles and 2-methylquinoline in good to excellent yields. These transformations do not require any transition metals or peroxides and tolerate various functional groups such as methoxy, hydroxy, bromo, chloro and nitro groups. Moreover, a plausible mechanistic pathway is proposed.
Natural Product-Mimetic Scaffolds with Privileged Heterocyclic Systems: Design, Synthesis, and Evaluation of Antioxidant Activity of Quinazoquinobenzothiazinones
Sharma, Kshitija,Khandelwal, Sarita,Samarth,Kumar, Mahendra
, p. 220 - 228 (2016)
(Chemical Equation Presented) Structurally diverse quinazolinoquinolinobenzothiazinones based on rutaecarpine structural framework with hybrid structural features of three medicinally privileged heterocyclic systems has been synthesized as natural product-mimetic scaffolds involving the use of multi-step reaction sequences. The synthesized quinazolinoquinolinobenzothiazinones have been evaluated for their antioxidant and radical scavenging activities.
Novel synthesis of benzothiazole by self-redox tandem reaction of disulfide with aldehyde
Liu, Bo,Zhu, Ning,Hong, Hailong,Han, Limin
, p. 9287 - 9292 (2015)
A novel methodology for the preparation of benzothiazole derivatives via the reaction of ortho-anilino disulfides with aryl and heteroaryl aldehydes catalyzed by Na2S·9H2O has been developed. The reaction mechanism was investigated by LC-MS and 1H NMR. The disulfide was cleaved firstly by the interchange reaction of the disulfide and metal sulfide, and the resulting thiol reacted in situ with the aldehyde to form the corresponding benzothiazoline. Subsequently, the intermediate benzothiazoline reduced the disulfide to thiol and it was oxidized to benzothiazole. The excess benzothiazoline was oxidized by air and both halves of the disulfide were ultimately converted to the desired benzothiazole.
Facile syntheses of 3-trifluoromethylthio substituted thioflavones and benzothiophenes via the radical cyclization
Wang, Lu,Wang, Huaiyu,Meng, Weidong,Xu, Xiu-Hua,Huang, Yangen
supporting information, p. 389 - 392 (2020/03/04)
3-CF3S substituted thioflavones and benzothiophenes were achieved via the reactions of AgSCF3 with methylthiolated alkynones and alkynylthioanisoles, respectively, promoted by persulfate. This protocol possesses good functional group tolerance and high yields. Mechanistic studies suggested that a classic two-step radical process was involved, which includes addition of CF3S radical to triple bond and cyclization with SMe moiety.
Iodine-catalyzed amination of benzothiazoles with KSeCN in water to access primary 2-aminobenzothiazoles
Chen, Xiran,Fu, Lianrong,Hao, Xin-Qi,Shi, Linlin,Song, Mao-Ping,Zhu, Xinju,Zhu, Yu-Shen
, (2021/09/09)
A facile and sustainable approach for the amination of benzothiazoles with KSeCN using iodine as the catalyst in water has been disclosed under transition-metal free conditions. The reaction proceeded smoothly to afford various primary 2-amino benzothiazoles in up to 96% yield. A series of control experiments were performed, suggesting a ring-opening mechanism was involved via a radical process. This protocol provides efficient synthesis of primary 2-aminobenzothiazoles
Rh-Catalyzed Asymmetric Hydrogenation of Unsaturated Medium-Ring NH Lactams: Highly Enantioselective Synthesis of N-Unprotected 2,3-Dihydro-1,5-benzothiazepinones
Yin, Congcong,Yang, Tao,Pan, Yingmin,Wen, Jialin,Zhang, Xumu
supporting information, p. 920 - 923 (2020/02/04)
A straightforward method to prepare 1,5-benzothiazepines was reported. Catalyzed by a Rh/Zhaophos complex, unsaturated cyclic NH lactams with a medium-size ring were hydrogenated smoothly, giving remarkably high enantioselectivities. The sulfur atom in the substrates did not bring an inhibition which was observed with commercially available bisphosphine ligands. This method was successfully applied in the scale-up synthesis of (R)-(-)-thiazesim.
Iodine- And TBHP-Promoted Acylation of Benzothiazoles under Metal-Free Conditions
Wang, Bin,Zhang, Qianwei,Guo, Zhongqi,Ablajan, Keyume
, p. 3058 - 3064 (2020/08/28)
A simple protocol for the synthesis of 2-acylbenzothiazoles using aryl ketones and benzothiazoles in the presence of I 2and TBHP is described. Acylation of the benzothiazoles is achieved through a sequence involving oxidation of the aryl ketone to an aryl glyoxal, ring-opening of the benzothiazole followed by condensation of the amino group with the aryl glyoxal, cyclization and oxidation. The method avoids the use of metals and toxic solvents. In addition, this protocol has the advantage of broad scope and provides good to excellent product yields.
Aerobic Dehydrogenation of N-Heterocycles with Grubbs Catalyst: Its Application to Assisted-Tandem Catalysis to Construct N-Containing Fused Heteroarenes
Kawauchi, Daichi,Noda, Kenta,Komatsu, Yoshiyuki,Yoshida, Kei,Ueda, Hirofumi,Tokuyama, Hidetoshi
supporting information, p. 15793 - 15798 (2020/10/12)
An aerobic dehydrogenation of nitrogen-containing heterocycles catalyzed by Grubbs catalyst is developed. The reaction is applicable to various nitrogen-containing heterocycles. The exceptionally high functional group compatibility of this method was confirmed by the oxidation of an unprotected dihydroindolactam V to indolactam V. Furthermore, by taking advantage of the oxygen-mediated structural change of the Grubbs catalyst, we integrated ring-closing metathesis and subsequent aerobic dehydrogenation to develop the novel assisted-tandem catalysis using molecular oxygen as a chemical trigger. The utility of the assisted-tandem catalysis was demonstrated by the concise synthesis of N-containing fused heteroarenes including a natural antibiotic, pyocyanine.
Preparation method of o-aminothiophenol
-
, (2020/12/30)
The invention provides a preparation method of o-aminothiophenol. The preparation method comprises the following steps: putting o-chloronitrobenzene into sodium methyl mercaptide, and performing heating under the action of a catalyst to carry out a methyl vulcanization reaction so as to prepare o-nitrophenyl dimethyl sulfide; putting o-nitrophenyl thioether into a solvent, and carrying out hydrogenation reduction to prepare o-aminobenzene thioether; and demethylating the o-aminothiophenol under the action of hydrobromic acid to obtain the o-aminothiophenol. The preparation method of o-aminothiophenol has the advantages of high yield and high product purity.
