Abstract Condensation of aminoguanidine hydrochloride and ethyl acetoacetate results in 2, 3-diamino-6-methylpyrimidin-4 (3 H)-one, 5-hydroxy-1-carboxamidino-3-methylpyrazole or ethyl N-[(5-hydroxy-3-methylpyrazol-1-yl) imidoyl] aminocrotonoate depending on the type of the base. Formation of pyrazole derivatives occurs in the case of dequaternized substrate imine-group protonating by the acids formed as a result of ion exchange reaction. Chelate ...
