Abstract
The reaction of dicyandiamide in the presence of hydrogen chloride as an acid catalyst in an inactive solvent (phenol or pyridine-nitrobenzene mixture) was studied.
The main reaction products were mono and diguanylmelamine. The amount of the acid present had a large effect on yields of the reaction products and in the presence of larger amount of the acid the yield of monoguanylmelamine was larger. It is remarkable that cyanamide was formede in the reaction, since it was suggested that cyanamide contributes to the formation of polyguanylmelamines. When dicyandiamide dihydrochloride was heated in phenol, guanyl-O-phenylisourea hydrochloride was produced in good yield.
The suitable reaction conditions for preparing monoguanylmelamine were found and a convenient method for isolating it was also established.
Some mechanistic implications of these results are briefly discussed.
