| 摘要 |
PURPOSE:To produce easily sodium dicyanamide having high purity in high yield by allowing cyanogen chloride to react with ammonia, extracting ammonium dicyanamide in the reaction product with acetone, and allowing the extracted ammonium dicyanamide to react with NaOH. CONSTITUTION:Cyanogen chloride is dissolved in a solvent such as benzene, and the reaction expressed by formula I is caused by blowing ammonia into the soln. Then, a mixture of crude crystals of obtd. ammonium dicyanamide and ammonium chloride are washed with acetone, thus ammonium dicyanamide alone in the mixture of the crude crystals is dissolved. Aq. NaOH is then added to the obtd. washing liquid, and the reaction expressed by formula II is caused by heating the liquid under reduced pressure, evaporating simultaneously the acetone, after, and ammonia. Thus, aimed sodium dicyanamide is obtd. as residue after evaporation. The obtd. sodium dicyanamide is used for a raw material for chlorohexidine which is one of the nontoxic disinfectants.
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