2,4,6-triamino-1,3,5-triazinealkylammonium alkyl- phosphonates -(C3H6N6R)+-OP(O)(X) (OR) (X=H, CH3; R=CH3; C2H5) and 2,4,6-triamino-1,3,5-triazineammonium dimethyl phosphate were synthesized (X=OCH3; R=CH3). When R=CH3 these salts decompose evolving carbene "CH2" and convert into the corresponding ammonium salts {C3H7N6}+-OP(O)(X)(OR). It has been established that when X=OCH3 and R=CH3 alkylammonium salts quantitatively convert into the corresponding ammonium salts. It has been assumed that the low basicity of the amino groups of the monoalkylated melamine is the reason to obtain only monoalkylated products.