The two steps synthesis of 2-hydrazonophenylselenoacetamides is described s
tarting from sulfur analogs. Depending on the substitution of hydrazono and
selenamide groups they allow the preparation of a 1,2,3-selenadiazolium sa
lt, a 5-imino-Delta (3)-1,2,3-selenadiazoline, 3,6-dihydro-2H-1,3,4-selenad
iazines and a 5-selenoxo-2,3,4,5-tetrahydro-1,2,4-triazin-3-one.