FIELD: chemistry.SUBSTANCE: present invention relates to complex iron compound (III). Compound contains at least one ligand of formula (I): , where arrows denote coordination connection with one or different iron atoms, R1 is selected from group consisting of linear or branched C1-8-alkyl, which can be substituted with C1-6-alkoxy (RO-), where R denotes unsubstituted alkyl, or C1-8-alkoxycarbonyl (RO-CO-), where R denotes unsubstituted alkyl； R2 is selected from group consisting of hydrogen atom, unsubstituted C1-8-alkyl, halogen atoms and cyano group, or R1 and R2, together with carbon atoms with which they are bonded form unsubstituted 5- or 6-member ring, R3 and R4 are respectively selected from group consisting of hydrogen atoms, morpholinyl, C3-6-cycloalkyl and linear or branched C1-8-alkyl which can be substituted with hydroxy, alkoxy, cycloalkyl, C1-8-alkoxycarbonyl (RO-CO-), where R denotes unsubstituted alkyl, or R3 and R4, together with nitrogen atom with which they are bonded form optionally substituted 3-6-member ring which optionally can contain one or more additional heteroatoms selected from N and O, or its pharmaceutically acceptable salts. Also disclosed is use of complex compounds and pharmaceutical composition.EFFECT: obtained compounds are intended for use as therapeutic agents for treating and/or preventing symptoms of iron deficiency and iron-deficiency anaemia.16 cl, 1 tbl, 80 exНастоящее изобретение относится к комплексному соединению железа(III). Соединение содержит по меньшей мере один лиганд формулы (I):где стрелки означают координационную связь с одним или разными атомами железа, R1 выбран из группы, состоящей из линейного или разветвленного C1-8-алкила, который может быть замещен C1-6-алкокси (RO-), где R означает незамещенный алкил, или C1-8-алкоксикарбонила (RO-CO-), где R означает незамещенный алкил； R2 выбран из группы, состоящей из атома водорода, незамещенного С1-8-алкила, атома галогена и цианогруппы, или R1 и R2, вместе с атома
