- Method for preparing aldehyde and acid by electrochemical dehydrochlorination of polychloromethylpyridine derivatives
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The invention discloses a method for preparing aldehyde and an acid by electrochemical dechlorination of a polychloromethylpyridine derivative, the method comprises the following steps: dissolving thepolychloromethylpyridine derivative in an acetic acid and acetate- containing buffer solution to obtain an electrolytic reaction solution; taking the electrolytic reaction solution as a cathode liquid, performing electrolytic reduction dechlorination reaction at a cathode, and hydrolyzing in the solution to obtain a polychlorinated pyridylaldehyde or acid derivative. The polychloromethylpyridinederivative is shown in formula (I), and the product polychlorinated pyridylaldehyde or acid derivative is shown in formula (II): in the formula (I), m is 0, 1, 2, 3 or 4, n is 0 or 1, and R' is an easy-to-oxidize or easy-to-hydrolyze substituent. The m and the R' in the formula (II) are same as that in the formula (I), R is H or OH, no waste acid is generated in the preparation process, the easy-to-oxidize or easy-to-hydrolyze substituent contained in the polychloromethylpyridine derivative and carbon-chlorine bonds on pyridine rings are not affected, and the recovery conversion rate is high.
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Paragraph 0035-0037; 0057-0060
(2020/08/27)
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- 3, 4, 5, 6-tetrachloropyridine method for the preparation of formic acid
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The invention provides a preparation method of 3,4,5,6-tetrachloropyridine-2-carboxylic acid. The method comprises the following steps: with waste residue generated in production of picloram or waste obtained after further purification of the waste residues generated in production of the picloram as raw material, adding nitrite for diazotization by the effects of strong acid and an inert diluent; adding a chlorine substituting agent for chlorination reaction to prepare the 3,4,5,6-tetrachloropyridine-2-carboxylic acid. A small amount of other isomerides generated during an ammonolysis process of tetrachloropyridine-2-carboxylic acid during circular processing and treatment of the method can be used for transforming non-pesticide components in the waste residues into raw production materials with practical values, so that the emission of the waste residues is reduced as far as possible. The prepared 3,4,5,6-tetrachloropyridine-2-carboxylic acid is higher than 95% in effective content and can satisfy the requirements on raw materials for industrial production of the picloram.
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Paragraph 0053; 0054; 0055; 0056; 0057
(2016/10/07)
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- Palladium-catalyzed carbonylation of polychlorinated pyridines. A simple laboratory approach to metal catalyzed carbonylation reactions
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The palladium-catalyzed carbonylation reactions of pentachloropyridine and 2,3,4,5-tetrachloropyridine were investigated in alcoholic or aqueous solvent. The high boiling alcohol 2-ethyl-1-hexanol was an effective carbonylation solvent above 100 °C at 1 atm of CO, representing a convenient and simple method for carrying out transition metal catalyzed carbonylation reactions using standard laboratory glassware.
- Hull Jr., John W.,Wang, Chen
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p. 411 - 417
(2007/10/03)
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