- Synthetic method of 3, 5-dibromopyridine
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The invention discloses a synthetic method of 3, 5-dibromopyridine. The synthetic method comprises the following steps of: (1) bromination reaction: dissolving 4-aminopyridine and azodiisobutyronitrile in carbon tetrachloride; adding N-bromosuccinimide at the temperature of 25 DEG C, carrying out central-control monitoring using a liquid phase till the reaction is complete, and treating to obtain 3, 5-dibromo-4-aminopyridine; (2) diazotization reaction: adding the 3, 5-dibromo-4-aminopyridine into concentrated sulfuric acid, dripping nitrosylsulfuric acid at the temperature of 48-55 DEG C after completely dissolving, stopping dripping when potassium iodide starch test paper is blue and does not fade, and then reacting for 1-1.5 hours; and (3) reduction reaction: continuously adding nickel powder and anhydrous ethanol solution into the solution, then carrying out refluxing reaction, cooling and then adjusting to be weakly alkaline by using concentrated sodium-hydroxide solution, and treating to obtain the 3, 5-dibromopyridine. The synthetic method disclosed by the invention has the advantages that the reaction condition is mild, the yield is high, the materials are easily available, the cost is lower, the process route is short, and the product purity is high and has industrial prospect.
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