Mercuriammonium chloride

Diphenyl-l,2,4-thiadiazole results in small quantities, together with 2,4,6-triphenyltriazine and other products, from the action of alcoholic ammonia and mercuric oxide, or mercuriammonium chloride, or lead hydroxide on A-thiobenzoylbenzamidine (78 R = Ph),10B and from the treatment of the mercuric chloride-adduct of this substituted amidine (78 R = Ph) with potassium hydroxide104 (probably by air oxidation). 

This salt was formerly named mercuriammonium chloride. Prepare a solution of 10 g. of mercuric chloride and to this slowly add a dilute solution of ammonium hydroxide as long as a precipitate is produced, avoiding an excess. Collect the precipitate on a filter, washing it once or twice with water. Too much washing is to be avoided, since the salt turns yellow from hydrolysis. Dry the precipitate on porous paper. 

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