Improved syntheses in the pyrimidine series. V. some derivatives of 4‐methylaminopyrimidine

The preparation of several derivatives of 4‐methylaminopyrimidine is described. When 2‐chloro‐4‐methylamino‐5‐nitropyrimidine is treated with aqueous sodium hydrogen sulphide, not only is the expected 5‐amino‐2‐mercapto‐4‐methylaminopyrimidine formed but also 5‐amino‐2: 6‐dimercapto‐4‐methylaminopyrimidine. Improved ways of making 5‐aminocytosine (4: 5‐diamino‐2‐hydrpxypyrimidine) and 2: 4: 5‐triaminopyrimidine, viz. by catalytic reduction of the corresponding 5‐nitro compounds, are reported.