FIELD: chemical industry. SUBSTANCE: present invention describes method of regeneration of N-C-N compound from sulfur binding reaction product which is widely used in chemical technology. In this case N-C-N compound is compound of formula (I): 
wherein n is 1, and each of R1-R5 is independently selected from group consisting of (i) hydrogen, (ii) substituted or unsubstituted, saturated or unsaturated linear, branched or cyclic hydrocarbon chain containing from 1 to 20 carbon atoms, (iii) substituted or unsubstituted, saturated or unsaturated linear, branched or cyclic hydrocarbon chain containing from 1 to 20 carbon atoms and comprising at least one heteroatom selected from group consisting of nitrogen and sulfur, (iv) directed bond with any other from R1,R2,R3,R4,R5, said product comprises hetero compound having sulfur, carbon and nitrogen atoms in main chain including stages (a) mixing of said product with (1) nitrogen-containing compound of formula II: 
wherein each of R6 and R7 is independently selected from group consisting of (i) hydrogen, (ii) substituted or unsubstituted, saturated or saturated, linear, branched or cyclic hydrocarbon chain containing from 1 to 20 carbon atoms, or salt thereof of (2) alkaline compound selected from group consisting of alkali or alkaline-earth metal compounds to form solution, suspension or dispersion, (b) reaction of said hetero-compound with said nitrogen-containing compound in the presence of said alkaline compound with substitution of sulfur atom of hetero-compound with nitrogen atom of nitrogen-containing compound and (c) if desired, pH of said solution is adjusted to values of about 8 to 13. Present invention describes another two methods of regeneration of N-C-N compound from sulfur binding reaction product. Methods are simple and are much more cheaper than well known methods. EFFECT: more efficient regeneration method. 18 cl, 10 ex
