The compounds 5,6‐dihydro‐4H‐imidazo[4,5‐c][1,2,5]oxadiazole (3a, RH), 4,6,10,12‐tetramethyl‐5,6,11,12‐tetrahydro‐4H,10H‐bis(1,2,5)oxadiazolo[3,4‐d:3′,4′‐I][1,3,6,8]tetraazecine (4b, RCH3), N3,N3′‐methylenebis‐3,4‐diamino‐1,2,5‐oxadiazole (5a, RH) and N3,N3′‐methylenebis(N,N′‐dimethyl‐3,4‐diamino‐1,2,5‐oxadiazolee) (5b, RCH3) were synthesized from the reaction of formaldehyde with 3,4‐diamino‐1,2,5‐oxadiazole and N,N′‐3,4‐dimethylamino‐1,2,5‐oxadiazole in an acetonitrile.