- Ruthenium(II)-Catalyzed Regioselective C-8 Hydroxylation of 1,2,3,4-Tetrahydroquinolines
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Ru(II)-catalyzed chelation-assisted highly regioselective C8-hydroxylation of 1,2,3,4-tretrahydroquinolines has been developed. Various 1,2,3,4-tetrahydroquinolines underwent smooth C8-H hydroxylation with cheap and safe K2S2O8 as the oxidant and oxygen source to furnish the corresponding products in good to excellent yields with high tolerance of the functional groups. The choice of a readily installable and removable N-pyrimidyl directing group is the key to catalysis. Mechanistic studies suggest the involvement of a six-membered ruthenacycle intermediate in the catalytic cycle. The method can also be extended to the direct hydroxylation of other (hetero)arene C-H bonds.
- Chen, Changjun,Pan, Yixiao,Zhao, Haoqiang,Xu, Xin,Luo, Zhenli,Cao, Lei,Xi, Siqi,Li, Huanrong,Xu, Lijin
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supporting information
p. 6799 - 6803
(2018/11/21)
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- Synthesis method of 2-hydroxyl-4-bromobenzoic acid
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The present invention discloses a synthesis method of 2-hydroxyl-4-bromobenzoic acid, and belongs to the technical field of organic synthesis. According to the synthesis method disclosed by the present invention, the synthesis method comprises the following steps: using phenol as a raw martial; firstly adding nitric acid and sulfuric acid to generate 2-nitrophenol; then adding HCl and zinc powder to synthesize 2-amino phenol; heating in a water bath and adding CH3COCH to further generate 2-acetamidophenol; next, adding FeBr3 and Br2, and adding CaO2 and triiron tetroxide after the reaction is cooled; and thus generating the 2-hydroxyl-4-bromobenzoic acid disclosed by the present invention after the 2-acetamidophenol is changed into the 2-hydroxyl-4-bromobenzoic acid. The embodiment demonstrates that the synthesis method disclosed by the present invention is not only simple in operation and mild in reaction but also free of pollution, so that the product yield is higher than 89%, and the purity reaches more than 92%.
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Paragraph 0005; 0012; 0013
(2016/10/10)
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- Divergent reactivities of o-haloanilides with CuO nanoparticles in water: A green synthesis of benzoxazoles and o-hydroxyanilides
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In the present study, three divergent reaction paths emerged when o-haloanilides were subjected to CuO nanoparticles in water. o-Halo (I, Br) phenylbenzamides in the presence of CuO nanoparticles and Cs2CO 3 in water at 100 °C provided o-hydroxyphenyl benzamides as the major product. However, a complete change in selectivity was observed in the presence of an organic base/ligand (TMEDA), giving 2-arylbenzoxazole as the exclusive product. The above selectivities were not clearly distinct when the corresponding alkylamides were treated either in the presence or absence of the ligand. A number of o-halophenyl alkylamides provided either exclusively o-dehalogenated products or a mixture of o-dehalogenated and o-hydroxylated products, but none gave 2-alkylbenzoxazoles. In addition to the above selectivities, the use of an environmentally friendly solvent (water) and base, and the recyclability of the catalyst make this procedure a benign alternative to the existing methods for the synthesis of these molecules, viz. o-hydroxybenzamides and o-arylbenzoxazoles.
- Khatun, Nilufa,Guin, Srimanta,Rout, Saroj Kumar,Patel, Bhisma K.
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p. 10770 - 10778
(2014/03/21)
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- NEW GPR119MODULATORS
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The application relates to compounds of Formula (Ia): and pharmaceutically acceptable salts, solvates, hydrates, geometrical isomers, tautomers, optical isomersor N-oxides thereof. The application also relates to pharmaceutical compositions comprising these compounds and to the use of these compounds for the prophylaxis and treatment of medical conditions relating to disorders of the G-protein- coupled receptor GPR119, such as diabetes, obesity and osteoporosis.
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