222838-33-7Relevant articles and documents
Selective hydrogenation of nitroaromatics to: N -arylhydroxylamines in a micropacked bed reactor with passivated catalyst
Chen, Jian-Li,Cheng, Peng-Fei,Jiang, Zhi-Jiang,Su, Wei-Ke,Xu, Feng,Yu, Zhi-Qun
, p. 28585 - 28594 (2020)
In this contribution, a protocol was established for the selective catalytic hydrogenation of nitroarenes to the corresponding N-arylhydroxylamines. The reduction of 1-(4-chlorophenyl)-3-((2-nitrobenzyl)oxy)-1H-pyrazole, an intermediate in the synthesis of the antifungal reagent pyraclostrobin that includes carbon-chlorine bonds, benzyl groups, carbon-carbon double bonds and other structures that are easily reduced, was chosen as the model reaction for catalyst evaluation and condition optimization. Extensive passivant evaluation showed that RANEY-nickel treated with ammonia/DMSO (1 : 10, v/v) afforded the optimal result, especially with a particle size of 400-500 mesh. To combine the modified catalyst with continuous-flow reaction technology, the reaction was conducted at room temperature, rendering the desired product with a conversion rate of 99.4% and a selectivity of 99.8%. The regeneration of catalytic activity was also studied, and an in-column strategy was developed by pumping the passivate liquid overnight. Finally, the generality of the method was explored, and 7 substrates were developed, most of which showed a good conversion rate and selectivity, indicating that the method has a certain degree of generality.
2-[pyrazolyl and triazolyl-3′-oxymethylene]-phenyl-isoxazolones, triazolones and tetrazolones as pesticides and fungicides
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Page/Page column 36, (2010/11/08)
2-[Pyrazolyl- and triazolyl-3′-oxymethylene]phenylisoxazolones, -triazolones and -tetrazolones of formula I where: X is a group A, B or C, ?where # denotes the bond with the phenyl ring,Ra is hydrogen, halogen, alkyl or alkoxy,Rb is
