OPB-2045 can be obtained by several related ways: 1) The addition of 3,4-dichlorobenzylamine hydrochloride (I) to sodium dicyanamide (II) in refluxing acetonitrile gives 1-(3,4-dichlorobenzyl)-3-cyanoguanidine (III), which is then condensed with octylamine hydrochloride (IV) in refluxing mesitylene. 2) The treatment of S,S'-dimethyl(cyanoimino)dithiocarbonate (V) with aqueous ammonia and further reaction with 3,4-dichlorobenzylamine hydrochloride (I) yields intermediate (III), which is then condensed with (IV) as before. 3) By condensation of 3,4-dichlorobenzylamine hydrochloride (I) with 1-cyano-3-octylguanidine (VI) in refluxing mesitylene.