6135-33-7Relevant academic research and scientific papers
An efficient one-pot synthesis of: N, N ′-disubstituted ureas and carbamates from N -acylbenzotriazoles
Singh, Anoop S.,Kumar, Dhananjay,Mishra, Nidhi,Tiwari, Vinod K.
, p. 84512 - 84522 (2016/10/12)
A facile and high-yielding one-pot synthesis of carbamates and N,N′-disubstituted symmetrical ureas from N-acylbenzotriazoles has been devised. It is believed that, the intermediate acyl-azide undergo Curtius rearrangement and in different solvents gives different products i.e. carbamates in alcohols and N,N′-disubstituted symmetrical urea in THF.
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.
Synthesis and thermal stability of new polynitrostilbenes
Wei, Jianping,Li, Fangmei,Xu, Junhui,Peng, Xinhua
, p. 919 - 925 (2015/06/25)
New polynitrostilbenes were directly synthesised by the Knoevenagel condensation of aromatic aldehydes with nitrotoluenes. The differential scanning calorimetry results demonstrated that the introduction of an amino group and C≤C double bonds could improve the thermal stability.
Zinc Triflate Catalyzed C-Benzylation: Chemo- and Regioselective Route to Amido Substituted Diaryl and Arylheteroarylmethanes
Deshmukh, Mahesh Subhashrao,Srivastava, Ananya,Das, Biswajit,Jain, Nidhi
, p. 10041 - 10048 (2015/11/03)
An unprecedented zinc triflate catalyzed selective C-benzylation of anilides and heteroaryl amides with benzyl chlorides having electron-donating group at para-position is reported. The protocol offers moderate to high yield of para-amido substituted diaryl and arylheteroarylmethanes, uses cheap and easily available benzyl chlorides as the benzylating agent, catalytic amount of zinc triflate, and takes place under ambient conditions. Aminodiarylmethane derivatives can be obtained by hydrolysis of the corresponding amides. The methodology has also been applied for preparing dimethoxydiarylmethanes in good yields, which are the key precursors for synthesis of phenolic natural products.
Ultrasound promoted 'one pot' conversion of nitrocompounds to carbamates
Chandrasekhar,Narsihmulu,Jagadeshwar
, p. 771 - 772 (2007/10/03)
An efficient ultrasound promoted novel direct conversion of nitro compounds to N-(tert-butoxycarbonyl) amines and N-(ethoxycarbonylamines) is achieved using Sn-NH4Cl for the first time.
The Biodegradation of Low-molecular-weight Urethane Compounds by a Strain of Exophiala jeanselmei
Owen, Stephen,Otani, Takahito,Masaoka, Satoshi,Ohe, Tatsuhiko
, p. 244 - 248 (2007/10/03)
To further analyze the biodegradation of polyurethane polymers, we investigated the biodegradation of low-molecular-weight N-tolylcarbamate model compounds with structures closely resembling the urethane linkages found in polyurethanes based on tolylene-diisocyanate (TDT). Soil microflora were screened for microorganisms that were able to utilize toluene-2,4-dicarbamic acid, diethyl ester (compound 1) as the sole source of carbon, and the soil fungus Exophiala jeanselmei strain REN-11A was selected as the most effective strain. Several N-tolylcarbamate compounds were used, and it was found that REN-11A was able to degrade compound 1, as well as the related compound toluene-2,6-dicarbamic acid, diethyl ester, very efficiently. Further investigation showed that compound 1 was biodegraded to tolylene-2,4-diamine via the aromatic amine intermediates carbamic acid, (3-amino-4-methylphenyl)-, ethyl ester and carbamic acid, (5-amino-2-methylphenyl)-, ethyl ester.
Synthesis of Tetranitrotoluenes
Nielsen, Arnold T.,Christian, Stephen L.,Chafin, Andrew P.,Wilson, William S.
, p. 1714 - 1718 (2007/10/02)
New synthetic routes to the three isomeric tetranitrotoluenes 1-3 are described, including the previously unreported 2,3,4,5-tetranitrotoluene (1).Methods include peroxydisulfuric acid oxidation of trinitrotoluidines and hypophosphorous acid reduction of
PLATINUM COMPLEX CATALYZED REDUCTIVE N-CARBONYLATION OF NITROARENES TO THE CARBAMATES.
Watanabe,Tsuji,Takeuchi,Suzuki
, p. 3343 - 3348 (2007/10/02)
The platinum catalyst combined with triphenylphosphine, tin(IV) chloride, and triethylamine showed high activity for the reductive N-carbonylation of nitroarene in ethanol at 180 degree C under carbon monoxide of 60 kg cm** minus **2. From nitrobenzene, ethyl phenylcarbamate was obtained in 83% yield. Iron(III) chloride, aluminum chloride and titanium(IV) chloride could be used as Lewis acids in place of tin(IV) chloride. Various nitroarenes were transformed into corresponding carbamate in moderate to excellent yields with the platinum catalyst.
A Versatile New Synthesis of Quinolines and Related Fused Pyridines. Part 8. Conversion of Anilides into 3-Substituted Quinolines and into Quinoxalines
Meth-Cohn, Otto,Rhouati, Salah,Tarnowski, Brian,Robinson, Andrew
, p. 1537 - 1543 (2007/10/02)
Anilides (4) (ArNHCOCH2R) are readily converted into 2-chloro-3-R-quinolines (5) under Vilsmeier conditions and the 3-chloro-group may be removed with zinc and acetic acid yielding 3-substituted quinolines (7).When N-nitrosodialkylamines are used in place of dimethylformamide as the Vilsmeier agent, the anilides are converted into 2-chloroquinoxalines in low yields.Several by-products are formed and the mechanisms have been explored.Thus, the formation of ethyl N-arylcarbamate from the corresponding propionanilide is shown to involve an C->O alkyl migration related to a Wolff rearrangement, while N-arylformimidoyl dichloride (18), nitriles, and isocyanides are derived from C-C cleavage of the substituted side-chain.Variation of the acid chloride component of the Vilsmeier reagent or of the solvent was generally unproductive though use of phosphoryl bromide instead of the chloride caused conversion of anilides into bromoquinolines in low yields.
