- Process method for producing 3-ethyl formate-4-hydroxy-2-pyridone by utilizing carbon dioxide
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The invention discloses a process method for producing 3-ethyl formate-4-hydroxy-2-pyridone by utilizing carbon dioxide. The process method comprises the following steps: weighing a 4-hydroxy-6-alkyl-2-pyridone substrate, a catalyst and potassium tert-butoxide to be added into a Schleck bottle, degassing, and continuously introducing 1atm of carbon dioxide; adding a solvent, and reacting in an oilbath; performing after-treatment after the reaction is completed so as to obtain a 3-carboxyl-4-hydroxy-2-pyridone compound 2; carrying out an esterification reaction among the obtained compound 2,(1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride), 2-methylaminopyridine and ethanol; performing column chromatography isolation after the reaction is completed, thereby obtaining the 3-ethyl formate-4-hydroxy-2-pyridone 3. According to the process method disclosed by the invention, the used catalyst is wide in source and low in price; the preparation process is simple, the equipment requirement is low, the raw material is wide in source and low in cost, the toxicity is low, and industrial scale-up production is easily realized.
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Paragraph 0018; 0022; 0043-0044; 0053-0054
(2019/08/01)
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- A 2, 4 - dihydroxy - 6 - methyl-nicotinic acid ethyl ester preparation method (by machine translation)
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The invention discloses a 2, 4 - dihydroxy - 6 - methyl-nicotinic acid ethyl ester preparation method, the method is 3 - amino-crotonic acid ethyl ester with malonic acid diethyl ester in ethanol sodium under the action of the condensation and dick graceful esterclaye woods ester gram one after the condensation reaction to produce the product 2, 4 - dihydroxy - 6 - methyl-nicotinic acid ethyl ester. The method of the invention condensation and two-step responds the Claye woods ester gramdick graceful ester condensation reactions are carried out in the same system, significantly shortens the reaction time, greatly reduces the production cost, simple preparation method of the present invention, the reaction system is green, and the reaction conditions are not severe, the obtained product purity is up to 99% or more, and the yield can reach 80% or more, so it is suitable for industrial large-scale production. (by machine translation)
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Paragraph 0021; 0022
(2017/02/09)
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- Thermal Cyclization of 3-Acyl-4-azidopyridines to Isoxazolo[4,3-c]pyridines
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4-Azidopyridines such as 3-acetyl-4-azido-2-pyridones 3 or 4-azido-3-ethoxycarbonylpyridine 7 with reactive ortho-acyl substituents were obtained from the 4-hydroxy-2-pyridones 1, resp. 5 via 4-tosyloxy-2-pyridones 2 or the 2,4-dichloropyridine 6. DSC-ass
- Stadlbauer, Wolfgang,Fiala, Werner,Fischer, Michaela,Hojas, Gerhard
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