47460-66-2Relevant academic research and scientific papers
N-substituted carbamates syntheses with alkyl carbamates as carbonyl source over Ni-promoted Fe3O4 catalyst
Shang, Jianpeng,Guo, Xiaoguang,Shi, Feng,Ma, Yubo,Zhou, Feng,Deng, Youquan
, p. 328 - 336 (2011)
A series of catalysts of magnetic iron oxide containing Ni with different nickel content were prepared with co-precipitation method and tested in the syntheses of N-substituted carbamates from various amines and alkyl carbamates. Under the optimized reaction conditions, various N-substituted carbamates were successfully synthesized with 90-98% isolated yield. The catalyst could be recovered based on the magnetic property of the catalyst and reused for five runs without deactivation. The catalysts were characterized with X-ray photoelectron spectroscopy, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption, and Moessbauer spectroscopy analyses. The results showed that the catalytic activity may be derived from the delicate synergy between Ni and Fe species resulted in specific basic sites. Quasi in situ FT-IR and isotopic tracer revealed that the formation of substituted urea was the key step and the N-substituted carbamate was formed via further alcoholysis of the substituted urea.
N-Substituted carbamate synthesis using urea as carbonyl source over TiO2-Cr2O3/SiO2 catalyst
Wang, Peixue,Ma, Yubo,Liu, Shimin,Zhou, Feng,Yang, Benqun,Deng, Youquan
, p. 3964 - 3971 (2015/07/15)
The use of urea as an active form of carbon dioxide is a feasible way to substitute phosgene in the chemical industry. This paper reports an effective route for the synthesis of N-substituted carbamates from amines, urea and alcohols. Under the optimized reaction conditions, several important N-substituted carbamates were successfully synthesized in 95-98% yields over a TiO2-Cr2O3/SiO2 catalyst. The catalyst could be reused for several runs without deactivation. The catalysts were characterized by BET, XPS, XRD, and TPD, which suggested that the strength and amount of the acidic and basic sites might be the major reason for the high catalytic activity of TiO2-Cr2O3/SiO2.
Attempted Cycloaddition of N-Ethoxycarbonylmethyleneamine to N-Ethoxycarbonylazepine: Formation of 4,4'-Bis(ethoxycarbonylamino)diphenylmethane
Murphy, William S.,Raman, Krishna P.
, p. 447 - 448 (2007/10/02)
Three products were formed in the boron-trifluoride-catalysed reaction of N-ethoxycarbonylmethyleneamine with N-ethoxycarbonylazepine, N-ethoxycarbonylaniline (2), 4-(N-ethoxycarbonylaminomethyl)-N-ethoxycarbonylaniline (3), and 4,4'-bis-(N-ethoxycarbonylamino)diphenylmethane (4).Product (4) was independently synthesised.The mechanisms of formation of the products (2), (3), and (4) were established.
