Introduction. Vascular pathologies associated with thromboembolism are common complications and the leading cause of morbidity and mortality among patients of various nosological groups. Previously, we obtained water-soluble 2-hydroxy-4-oxo-4-R-2-butenoates of hetarylammonium, which exhibit a significant pharmacological effect on the blood coagulation system». A compound with a pronounced anticoagulant effect was found in various routes of administration. It was of interest to study various methods of confirming the authenticity of a potential anticoagulant.Aim. Development of methods for identification of a potential anticoagulant 2-hydroxy-4-oxo-(4-chlorophenyl)-2-butenoate of thiazolinammonium.Materials and methods. The studies were carried out on three series of the substance 2-hydroxy-4-oxo-(4-chlorophenyl)-2-butenoate of thiazolinammonium obtained in laboratory conditions. The melting point of BAS was measured by the capillary method according to GF XV OFS.1.2.1.0011 "Melting point". The solubility of the substance was determined in accordance with GF XV of the OFS.1.2.1.0005 "Solubility". The absorption spectra in the IR region were taken in accordance with GF XV of the OFS.1.2.1.1.0002 "Spectrophotometry in the middle infrared region". Absorption spectra in the UV region were taken in accordance with GF XV of the OFS.1.2.1.1.0003 "Spectrophotometry in the ultraviolet and visible regions". In carrying out qualitative reactions, reagents prepared in accordance with GF XV of the OFS were used.1.3.0001 "Reagents. Indicators".Results and discussion. A description of the substance has been carried out. The melting point and solubility of the compound were determined. Spectra in the IR and UV regions of the spectrum were taken. Methods were selected, and qualitative reactions of authenticity of a potential anticoagulant were carried out.Conclusion. The studied characteristics of the new BAS can be used in the standardization of the substance according to the indicators "Description", "Solubility", "Identification", "Melting point". These indicators characterize the physico-chemical properties of 2-hydroxy-4-oxo-(4-chlorophenyl)-2-butenoate of thiazolinammonium, and will be included in the draft regulatory documentation for the substance in the future.