N-Substituted 2,4-diamino-6-alkylthio- and 2-amino-4,6-dialkylthio-sym-triazines were synthesized using the C-2-C-5 mercaptan fraction isolated upon purification of wide-cut hydrocarbon fractions of Orenburg gas condensate. A high efficiency of the synthesized compounds as polyfunctional additives to the base oil M-11 and antioxidant additives to synthetic lubricating oils was shown.