Previously we have synthesised the derivatives of 2-merkapto-4-methyl-5-thiokso-1,3,4-thiadiazol were synthesised and compounds with high fungicidal activity were discovered among them. Taking this into account we have used more easily accessible 2-merkapto-5-thiokso-1,3,4-thiadiazol as an initial substance, which is alkylated by different alkylating agents. The obtained compounds were set in reaction with 2,4-dichlor-6-methylpirimidine. Application of para-chlorbenzol and 2,4-dichlor-6-methylpirimidine as alkylating agents made it possible to obtain bis-benzyl (pirimidinil-4)-1,3,4-thiadiazol.