The range of applications for 3,4-dihydropyrimidine-2-thiones has been expanded through the synthesis of a bioactive derivative of 3,4-dihydropyrimidine-2 (1H) thione known as Monastrol , which has shown a completely new mechanism of anti-cancer action, it is a cell-permeable small molecule inhibitor , inhibiting the activity of a cancer. Materials. Thiourea, urea, acetoacetic ether; Biginelli cyclization method. Monastrol is the result of a three-component one-pot synthesis based on the reaction of acetoacetic ether, thiourea and 3-hydroxybenzaldehyde in the presence of various catalysts. In the synthesis of monastrol, the goal is to select reagents and test various catalysts that are environmentally friendly, least toxic and financially attractive, in order to maximize the yield of the product, shorten the reaction time, selectivity and minimize excess reagents, the formation of by-products, high temperatures, environmental pollution. environment, waste and costs. Catalysis plays a fundamental role in the Biginelli synthesis, especially in the development of strategies to approach eco - friendly catalytic conditions for further use in the renewable chemical industry. Such catalytic conditions were provided by ionic liquids that do not lose their activity in at least five repeated syntheses and ensure the preservation of the environment.