27643-12-5Relevant academic research and scientific papers
Application of N-Acylbenzotriazoles in the Synthesis of 5-Substituted 2-Ethoxy-1,3,4-oxadiazoles as Building Blocks toward 3,5-Disubstituted 1,3,4-Oxadiazol-2(3H)-ones
Wet-Osot, Sirawit,Phakhodee, Wong,Pattarawarapan, Mookda
, p. 9923 - 9929 (2017/09/23)
5-Substituted-2-ethoxy-1,3,4-oxadiazoles were conveniently prepared through a one-pot sequential N-acylation/dehydrative cyclization between ethyl carbazate and N-acylbenzotriazoles in the presence of Ph3P-I2 as a dehydrating agent. Subsequent treatment with a stoichiometric amount of alkyl halides (X = Cl, Br, I) enables a rapid access to a variety of 3,5-disubstituted 1,3,4-oxadiazol-2(3H)-ones in good to excellent yields.
1,3-Dipolar Cycloaddition of Nitrile Imine with Carbon Dioxide: Access to 1,3,4-Oxadiazole-2(3H)-ones
Guo, Chun-Xiao,Zhang, Wen-Zhen,Zhang, Ning,Lu, Xiao-Bing
, p. 7637 - 7642 (2017/07/26)
Efficient synthesis of 1,3,4-oxadiazole-2(3H)-one was achieved by CsF/18-crown-6 mediated 1,3-dipolar cycloaddition of nitrile imine and 2.0 MPa of CO2. CsF/18-crown-6 played a key role in enhancing the reactivity of CO2 as a 1,3-dipolarophile. The practical utility of this transition-metal-free approach to 1,3,4-oxadiazole-2(3H)-one is highlighted by the convenient synthesis of a commercial herbicide Oxadiazon and a MAO B inhibitor.
Method for synthesizing 1,3,4-oxadiazole-2-one compounds of oxadiazon and the like by carbon dioxide
-
Paragraph 0061; 0062; 0063; 0064; 0065; 0066, (2017/07/20)
The invention discloses a method for synthesizing 1,3,4-oxadiazole-2-one compounds of oxadiazon and the like by carbon dioxide. The method comprises: adding an acyl halide hydrazone raw material and a solvent into a high-pressure autoclave; using alkali and an additive as accelerants, introducing carbon dioxide, and performing a stirring reaction for 6 to 24 hours at a temperature of 0 to 70 DEG C; after finishing the reaction, cooling to the room temperature; slowly releasing the unreacted carbon dioxide; after adding water to dilute reaction liquid, carrying out extraction by ethyl acetate; concentrating to obtain a crude product; purifying by column chromatography to obtain the 1,3,4-oxadiazole-2-one compounds. The method disclosed by the invention uses the carbon dioxide for replacing conventional phosgene and carbon monoxide, is safe and simple to operate, low in toxicity, friendly to the environment, simple and easy for obtaining reaction raw materials and reagents, wide in universality of a type of a reaction substrate, simple in post-processing process, high in target product yield and beneficial to industrial production, and is widely applied in synthesis of pesticides, medicines and natural products.
I2 mediated synthesis of 5-substituted-3-methyl/benzyl-1,3,4-oxadiazol-2(3H)-ones via sequential condensation/oxidative cyclization and rearrangement
Patel, Shyam Sunder,Chandna, Nisha,Kumar, Shreemoyee,Jain, Nidhi
, p. 5683 - 5689 (2016/07/06)
A simple and efficient iodine-assisted protocol for the synthesis of 5-substituted-3-methyl/benzyl-1,3,4-oxadiazol-2(3H)-ones has been developed. The reaction involves a sequential condensation followed by tandem oxidative cyclization and rearrangement of
The use of a Mitsunobu reagent for the formation of heterocycles: A simple method for the preparation of 3-alkyl-5-aryl-1,3,4-oxadiazol-2(3H)-ones from carboxylic acids
Sugimoto, Osamu,Arakaki, Tomoyo,Kamio, Hiroka,Tanji, Ken-Ichi
supporting information, p. 7314 - 7317 (2014/07/07)
The reaction of carboxylic acids with Mitsunobu reagents, prepared by the reaction of triphenylphosphine with dialkyl azodicarboxylates, followed by heating at 180-190 °C under solvent-free conditions, afforded 3-alkyl-5-aryl-1,3,4-oxadiazol-2(3H)-ones. This facile and convenient method readily provides the 1,3,4-oxadiazolone ring systems in good yields using a one-pot protocol starting from the corresponding carboxylic acids. It was also demonstrated that the presence of a catalytic base facilitates the final ring closure forming the 1,3,4-oxadiazol-2(3H)-one.
Propylene oxide assisted one-pot, tandem synthesis of substituted-1,3,4- oxadiazole-2(3H)-ones in water
Yan, Xu,Zhou, Shuo,Wang, Yuanqiang,Ge, Zemei,Cheng, Tieming,Li, Runtao
, p. 7978 - 7983 (2012/09/21)
It has been developed for the synthesis of substituted-1,3,4-oxadiazole- 2(3H)-one derivatives via a novel one-pot, tandem procedure assisted by propylene oxide. The 5-substitued-1,3,4-oxadiazole-2(3H)-ones and 3,5-disubstitued-1,3,4-oxadiazole-2(3H)-ones were, respectively, obtained from three-component reaction of acylhydrazines, carbon disulfide, and propylene oxide, and four-component reaction of acylhydarazines, carbon disulfide, propylene oxide, and organic halides. The reactions were carried out using water as solvent in the presence of potassium phosphate to afford the expected products in good to excellent yields.
Verdazyl radicals as substrates for organic synthesis: A synthesis of 3-methyl-5-aryl-1,3,4-oxadiazolones
Bancerz, Matthew,Georges, Michael K.
experimental part, p. 6377 - 6382 (2011/10/05)
The synthesis of oxadiazolones under hydrolytic conditions is described for a series of 3-methyl-5-aryl-1,3,4-oxadiazolone compounds. The unique starting materials for the hydrolysis reaction are obtained from efficient 1,3-dipolar cycloaddition reactions
Syntheses and thermal rearrangements of 2-phenyl-4-alkoxycarbonyl-1,3,4-oxadiazol-5(4H)-ones and related sulfur compounds
Golfier, M.,Guillerez, M. G.
, p. 71 - 80 (2007/10/02)
Syntheses of nine 2-phenyl-4-alkoxycarbonyl-1,3,4-oxadiazol-5(4H)-ones are described.On heating about 200 deg C, these compounds decarboxylate and give 2-phenyl-4-alkyl-1,3,4-oxadiazol-5(4H)-ones.Although many analogies suggest that the rearrangement proceeds through the cyclisation of a 1,5-dipole, arising from the decarboxylation of the heterocycle, no direct evidence for such a mechanism was obtained.On the contrary, the synthesis and the thermal rearrangement of four related sulfur compounds show that such a postulated intermediate cannot explain all the experimental results.
