A Simple and Efficient Method for the Oxidation of Aryl Substituted Semicarbazide with NaNO<sub>2</sub>/NaHSO<sub>4</sub>·H<sub>2</sub>O/SiO<sub>2</sub>under Mild Conditions
作者:Xiao-Chuan Li、Yu-Lu Wang、Jin-Ye Wang
DOI:10.1002/jccs.200200062
日期:2002.6
In this paper, eighteen aryl substituted semicarbazide underwent efficient oxidation to aryl azo compounds using NaNO 2 /NaHSO 4 .H 2 O/SiO 2 under mild conditions with excellent yields.
Abstract Using 4-hydroxy-2,2,6,6-tertramethyl-l-piperidinyloxyl as the phasestransfer dehydrogenation catalyst to prepare azo compounds is reported first time, ten N, 2-diaryl diazenecarboxamides were synthesized in high yield under mild condition. A possible mechanism was suggested by a nitroxide free radical which acted on substituted semicarbazides to form azo compounds.
Novel compounds of the formula I in which X, Y, Z, R, R
1
, R
2
and R
3
are as defined in Patent claim
1
, are inhibitors of coagulation factor Xa and can be employed for the prophylaxis and/or therapy of tromboembolic diseases and for the treatment of tumours
1
A New and Efficient Solid State Synthesis of<i>N</i>-Aryl-2-Phenyldiazenecarboxamides
作者:Wan-Xin Xue、Jian-Ping Li、Wei-Li、Yu-Lu Wang
DOI:10.1002/jccs.200400148
日期:2004.10
An efficient and convenient solidstate reaction using Fe(N03) 3 .9H 2 O/NaHSO 4 .H 2 O to oxidize aryl-substituted semicarbazides for preparing azo compounds has been reported. Eight N-aryl-2-phenyldiazene-carboxamides have been synthesized in excellent yields at room temperature. The method is efficient and rapid.
Clean synthesis of azo compounds using Magtrieve™ in the ionic liquid [bmim][Br]
作者:Hui Wan、Yanqing Peng
DOI:10.1007/s00706-008-0869-5
日期:2008.8
A series of azo compounds, N-aryl-2-phenyldiazenecarboxamides, and 4-substituted-1,2,4-triazoline-3,5-diones, were synthesized using Magtrieve (TM), a magnetically retrievable and recyclable oxidant, in the ionic liquid [bmim][Br] under neutral condition. This procedure has several advantages, such as greenness, mild reactions, simple manipulation, and reusability of reagent and solvent.