- Synthesis of new mesomeric betaines containing a triazolopyridiniumolate system and their unexpected function as masked isocyanates
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A series of mesomeric betaines containing 1-alkylated triazolopyridiniumolate system were synthesized and their cycloaddition with dimethyl acetylenedicarboxylate were examined. An unusual ring-opening reaction occurred to give pyridone derivatives indicating that these betaines act as masked isocyanates.
- Sakai, Norio,Funabashi, Makoto,Minakata, Satoshi,Ryu, Ilhyong,Komatsu, Mitsuo
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- PIDA-Mediated Rearrangement for the Synthesis of Enantiopure Triazolopyridinones
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A tandem oxidative cyclization/1,2-carbon migration of hydrazides for the synthesis of otherwise inaccessible hindered or enantiopure triazolopyridinones has been developed. This protocol exhibits broad substrate scope and can be easily scaled up by continuous flow synthesis under mild conditions. Most importantly, this method demonstrates a rearrangement with retention of configuration and can be readily applied for the late-stage modification of carboxylic-acid-containing pharmaceuticals, amino acids, and natural products to access enantiopure triazolopyridinones.
- Ye, Zenghui,Zhang, Hong,Chen, Na,Wu, Yanqi,Zhang, Fengzhi
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- Method for preparing pyridino-triazolone compound through flow chemistry
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The invention relates to a method for preparing a pyridino- triazolone compound (II) through flow chemistry. The method comprises the following steps: a hydrazide compound (I) is dissolved in an organic solvent, the solution is placed in a first storage tank, an oxidantis dissolved in the organic solvent, and the solution is placed in a second storage tank; and aterials in the first storage tank and the second storage tank are conveyed through metering pumps respectively and enter a mixer to be mixed, reaction liquid obtained through mixing continuously enters a tubular reactor to be subjected to oxidation rearrangement reaction, the temperature of oxidation rearrangement is 0-70 DEG C, the retention time of the mixed reaction liquid in the tubular reactor is 0.1-10 h, material liquid obtained after reaction enters a receiving tank and is subjected to post-treatment, and after-treatment is conducted on the material liquid to obtain the product (II). In the tubular reaction, the material back mixing is less, the mass transfer and heat transfer efficiency is high, and the side reaction is obviously reduced; a reaction system is simple, raw materials, especially hydrazide compounds, are easily obtained, a substrate does not need to be prepared in multiple steps, and the total yield is relatively high; and the continuous tubular reaction can accurately control reaction parameters and has an automation prospect;.
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Paragraph 0024-0049
(2021/07/21)
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- Method for preparing pyridino-triazolone compound through oxidation rearrangement
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The invention relates to a method for preparing a pyridino-triazolone compound (II) through oxidative rearrangement. The method comprises the following steps: dissolving a hydrazide compound (I) in a solvent, adding an oxidant, stirring and reacting at 0-70 DEG C for 5-30 minutes, and post-treating the reaction liquid to obtain the product pyridino-triazolone compound (II). The reaction system is simple, raw materials, especially the hydrazide compound, are easy to obtain, a substrate does not need to be prepared in multiple steps, the total yield is high, the hydrazide compound can be oxidized by the chemical oxidizing agent to obtain the substituted pyridino-triazolone compound in one step, and the highest yield of the pyridino-triazolone compound is 99%.
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Paragraph 0019-0043
(2021/07/17)
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