1739-74-8Relevant academic research and scientific papers
One-pot synthesis of 1,3,4-oxadiazol-2(3H)-ones with CO2 as a C1 synthon promoted by hypoiodite
Yang, Na,Yuan, Gaoqing
, p. 6639 - 6644 (2019/07/16)
A convenient and efficient route has been developed to synthesize 1,3,4-oxadiazol-2(3H)-ones from CO2, hydrazines and aryl or aliphatic aldehydes. Promoted by hypoiodite (IO-) generated in situ from KI and oxidant TBHP, the one-pot synthesis could proceed smoothly to afford the desired products in moderate to high yields. Mechanism studies revealed that nitrile imine was an important intermediate in this transformation. Notably, a commercial herbicide Oxadiazon could be successfully synthesized by this route.
Method for synthesizing 1,3,4-oxadiazole-2-one compounds of oxadiazon and the like by carbon dioxide
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Paragraph 0055; 0056; 0057; 0058; 0059; 0060, (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.
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.
