Quinoline chlorozincate

The mixed amines are dissolved in hydrochloric acid and zinc chloride solution added. The quinoline chlorozincate, (C H7N)2,HtZnCl, crystallises out, being almost insoluble in water, while the aniline chlorozincate remains in solution. The quinoline chlorozincate is then filtered off and decomposed by alkalis, and the liberated quinoline extracted with ether or steam-distilled. 

Transfer the quinoline chlorozincate to a beaker, add a small quantity of water, and then add 10% sodium hydroxide solution until the initial precipitate of zinc hydroxide completely redissolves, and the free quinoline separates. Transfer the mixture to a separating-funnel, wash out the beaker with ether, adding the washings also to the solution in the funnel, and then extract the quinoline twice with ether. Dry the united ethereal extracts by adding an ample quantity of powdered potassium hydroxide and... 

Several chemical methods are used. In one method the mixture of aniline and quinoline is acylated either with acetic anhydride or with sulfochloride. The aniline forms a derivative and the quinoline remains unaffected. A second method treats the mixture with sodium nitrite and sulfuric acid. The aniline is converted into the diazonium salt and the quinoline forms the sulfate. The solution is made alkaline and steam-distilled the diazonium salt changes to sodium phenoxide, and quinoline is distilled. In the third method, the mixture is separated by means of hydrochloric acid and zinc chloride. Quinoline chlorozincate, (C9H7N)2H2ZnCl4, is sparingly soluble in water and is separated from the soluble anihne salt. 

These chlorozincates must not be confused with the non-ionic compounds which quinoline and aniline bases give with neutral zinc chloride the latter have the formulae [(C,H7N)2ZnClt] and [(C,H7N)tZnCl ] respectively, and both are only slightly soluble in water. 

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