32329-20-7Relevant academic research and scientific papers
Synthesis, Crystal Structure, and Biological Activity of 4-phenoxyacetyl-substituted methyl-3,4-dihydro-2H-1,4-benzoxazine
Kang, Tao,Liu, Cheng-Guo,Qu, Hai-Tao
, p. 259 - 264 (2021/08/03)
Two novel substituted benzoxazine derivatives have been synthesized through reduction, cyclization, and acylation reactions. The target compounds were characterized by IR, 1H-NMR, 13C-NMR, and HRMS. The single-crystal structures of t
Design, synthesis and evaluation of novel trichloromethyl dichlorophenyl triazole derivatives as potential safener
Guo, Ke-Liang,Zhao, Li-Xia,Wang, Zi-Wei,Rong, Shu-Zhe,Zhou, Xiao-Lin,Gao, Shuang,Fu, Ying,Ye, Fei
, (2019/10/22)
The dominance of safener can unite with herbicides acquiring the efficient protection of crop and qualifying control of weeds in agricultural fields. In order to solve the crop toxicity problem and exploit the novel potential safener for fenoxaprop-P-ethyl herbicide, a series of trichloromethyl dichlorobenzene triazole derivatives were designed and synthesized by the principle of active subunit combination. A total of 21 novel substituted trichloromethyl dichlorobenzene triazole compounds were synthesized by substituted aminophenol and amino alcohol derivatives as the starting materials, using cyclization and acylation. All the compounds were unambiguously characterized by IR,1H-NMR,13C-NMR, and HRMS. A greenhouse bioassay indicated that most of the title compounds could protect wheat from injury caused by fenoxaprop-P-ethyl at varying degrees, in which compound 5o exhibited excellent safener activity at a concentration of 10 μmol/L and was superior to the commercialized compound fenchlorazole. A structure–activity relationship for the novel compounds was determined, which demonstrated that those compounds containing benzoxazine groups showed better activity than that of oxazole-substituted compounds. Introducing a benzoxazine fragment and electron-donating group to specific positions could improve or maintain the safener activity for wheat against attack by the herbicide fenoxaprop-P-ethyl. A molecular docking model suggested that a potential mechanism between 5o and fenoxaprop-P-ethyl is associated with the detoxication of the herbicide. Results from the present work revealed that compound 5o exhibited good crop safener activities toward wheat and could be a promising candidate structure for further research on wheat protection.
Metal-free tandem cyclization/hydrosilylation to construct tetrahydroquinoxalines
Pan, Yixiao,Chen, Changjun,Xu, Xin,Zhao, Haoqiang,Han, Jiahong,Li, Huanrong,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
supporting information, p. 403 - 411 (2018/02/07)
A one-pot tandem procedure involving cyclization and sequential hydrosilylation of imines and amides under the catalysis of B(C6F5)3 has been developed for the step-economical construction of 1,2,3,4-tetrahydroquinoxalines directly from readily available 1,2-diaminobenzenes, α-ketoesters and low-cost, safe polymethylhydrosiloxane (PMHS). This metal-free approach provides various products in good to excellent yields, and displays a wide range of substrate scope and a high degree of functional group tolerance even to reduction-sensitive moieties. The choice of hydrosilanes is critical to the catalysis, and PMHS has proved to be optimal. Decreasing the amount of PMHS could enable the reaction to stop at the 3,4-dihydroquinoxalin-2(1H)-one stage. The procedure is convenient and scalable, and neither a dried solvent nor an inert atmosphere is required. Moreover, the enantioselective construction of these products was explored, and promising results were achieved.
Synthesis of Nonracemic 1,4-Benzoxazines via Ring Opening/Cyclization of Activated Aziridines with 2-Halophenols: Formal Synthesis of Levofloxacin
Mal, Abhijit,Wani, Imtiyaz Ahmad,Goswami, Gaurav,Ghorai, Manas K.
, p. 7907 - 7918 (2018/06/11)
Novel 3,4-dihydro-1,4-benzoxazine derivatives have been synthesized by an efficient and simple method in excellent enantio- and diastereospecificity (ee > 99%, de > 99%). The reaction proceeds via Lewis acid-catalyzed SN2-type ring opening of activated aziridines with 2-halophenols followed by Cu(I)-catalyzed intramolecular C-N cyclization in a stepwise fashion under one-pot conditions to furnish the 3,4-dihydro-1,4-benzoxazine derivatives in excellent yields (up to 95%). The strategy offers a short and efficient synthesis to (S)-3-methyl-1,4-benzoxazine (S)-3v, a late stage intermediate in the synthesis of levofloxacin.
Ruthenium-Catalyzed Amination of Secondary Alcohols Using Borrowing Hydrogen Methodology
Marichev, Kostiantyn O.,Takacs, James M.
, p. 2205 - 2210 (2016/04/26)
A new ruthenium complex catalyzes the amination of primary and secondary alcohols and the regioselective mono- and sequential diamination of diols via the borrowing hydrogen pathway. Several variations on new intra- and intermolecular cyclizations of aminoalcohols, diols, and diamines lead to heterocyclic ring systems.
Chemoenzymatic Asymmetric Synthesis of 1,4-Benzoxazine Derivatives: Application in the Synthesis of a Levofloxacin Precursor
López-Iglesias, María,Busto, Eduardo,Gotor, Vicente,Gotor-Fernández, Vicente
, p. 3815 - 3824 (2015/05/04)
A versatile and general route has been developed for the asymmetric synthesis of a wide family of 3-methyl-3,4-dihydro-2H-benzo[b][1,4]oxazines bearing different pattern substitutions in the aromatic ring. Whereas hydrolases were not suitable for resoluti
Synthesis and safener activity of novel substituted 4-phenoxyacetyl-1,4-benzoxazines
Ye, Fei,Wu, Shi-Long,Zhao, Li-Xia,Qu, Hai-Tao,Gao, Shuang,Fu, Ying
, p. 1256 - 1268 (2015/07/15)
A novel class of 3-methyl-4-phenoxyacetyl-3,4-dihydro-2H-1,4-benzoxazine 3 were synthesized via reduction, cyclization, and acylation reactions. The structures of the compounds were characterized by IR, 1H-NMR, 13C-NMR, MS, and elemental analyses. The configuration of 3f was determined by X-ray crystallography. The bioassay results demonstrated that most of these compounds could alleviate 2,4-D butylate injury to maize.
Synthesis, crystal structure and biological activity of novel substituted nacetoxyacetyl- 3-methyl-3,4-dihydro-2H-1,4-benzoxazine
Ye, Fei,Wu, Shi-Long,Gao, Shuang,Fu, Ying
, p. 481 - 486 (2019/01/21)
A series of novel substituted 4-acetoxyacetyl-3-methyl-3,4-dihydro-2H-1,4- benzoxazines has been synthesized by cyclization and acylation with 1-(onitrophenoxyl) acetone and acetoxyacetyl chloride as the starting material. The structures of the compounds were characterized by IR, 1H and 13C NMR, MS spectroscopy and elemental analysis. The configuration of 3c was determined by Xray crystallography. The biological activity tests indicated that the compounds could protect maize against the injury caused by 2,4-D butylate in some extent.
Synthesis, crystal structure and biological activity of ndichloroacetyl- 3,4-dihydro-3-methyl-2h-1,4-benzoxazines
Fu, Ying,Wang, Jiao,Zhao, Qing-Shan,Wang, Xin-Ming,Xing, Zhi-Yong,Ye, Fei
, p. 41 - 46 (2019/01/21)
A three-step sequence was developed for synthesizing N-dichloroacetyl-3,4-dihydro- 3-methyl-2H-1,4-benzoxazine. Compounds 4 were obtained via O-alkylation, reduction, cyclization and acylation with o-nitro phenol and chloroacetone as the starting material. The structures of the compounds were characterized by IR, 1H NMR, 13C NMR, MS spectroscopy and elemental analysis. The configuration of 4a was determined by Xray crystallography. The preliminary biological test showed that the compounds could protect maize against injury by acetochlor in some extent.
Synthesis of dihydrobenzoheterocycles through Al(OTf)3-mediated cascade cyclization and ionic hydrogenation
Tian, Yulin,Wang, Xiaojian,Xiao, Qiong,Sun, Chenbin,Yin, Dali
, p. 9678 - 9685 (2015/02/05)
A facile and versatile synthesis of dihydrobenzoheterocycles via Al(OTf)3-mediated cascade cyclization and ionic hydrogenation has been developed. The reaction is applicable to a wide range of substrates with various functional groups to afford the corres
