The problem of acid corrosion of steel is of signifi cant importance, particularly in the context of the oil extraction industry, where acid treatment of wells and surrounding spaces is widely employed. This research article focuses on the synthesis and investigation of previously unstudied derivatives of the class of 2-alkyl-5-phenyl-4,5,6,7-tetrahydro-[1,2,4]triazolo[1,5-a]pyrimidin-7-ols – organic compounds potentially highly eff ective as inhibitors of acid corrosion of steel. The method for synthesizing the proposed compounds involves the condensation of 3-alkyl5-amino-1H-1,2,4-triazoles with cinnamaldehyde. The structure of the synthesized compounds has been confi rmed using 1H NMR and LCMS methods. The study has revealed that the developed synthesis conditions yield the target tetrahydrotriazolopyrimidinols with alkyl substituents containing up to three carbon atoms. However, an increase in the length of alkyl substituents intensifi es side reactions, making the isolation of the target compounds challenging. The obtained research results are signifi cant for the development of eff ective organic inhibitors of acid corrosion of steel of a new class. These fi ndings can serve as a basis for further research in this area, contributing to the development of new methods for corrosion prevention and improving the resistance of materials used in the oil industry. Thus, this study not only describes a new synthetic approach to obtaining inhibitors of corrosion in the tetrahydrotriazolopyrimidinol class but also holds prospective practical value in the fi eld of industrial technologies and materials science.