Abstract
Catalytic reduction of cyanamide by use of palladium catalyst has been investigated and a process of obtaining of f ormamidine salt, which was difficult in its preparation heretofore, with high yield was found. The reductive reaction was proceeded smoothly at room temperature and normal pressure in the presence of ammoium salt or mineral acid. Since there wasno reductive side reaction during the progress of this reductive reaction, the procedure and the treatment of reaction product were very simple and obtaining the product with high purity was possible. Observation on the state of absorption of hydrogen indicated that the cyanamide itself had a strong action of catalyst poison. For this reason, a portionwise addition of cyanamide to well activated palladium catalyst was made during the progress of reaction and its poison effect was suppressed. By carrying the process of portionwise addition of cyanamide to effect the dilution of the catalyst, the amount of palladium required was able to decrease to 1.7% of the cyanamide. By this process, formamidine sulfate, was newly prepared and some properties of this compound were also studied
Experimental results indicated that this process has a value for practical application in the preparation of formamidine salt by using easily obtainable commercial cyanamide as a raw material.
