A new method for the synthesis of α-trifluoromethylated tertiary alcohols bearing coumarins is described. The reaction of 3-(trifluoroacetyl)coumarin and pyrrole provided the target compounds with high yields under catalyst-free, mild conditions. The crystal structure of compound 3fa was investigated by X-ray diffraction analysis. The biological activities, such as in vitro antifungal activity of the α-trifluoromethylated tertiary alcohols against Fusarium graminearum, Fusarium oxysporum, Fusarium moniliforme, Rhizoctonia solani Kuhn, and Phytophthora parasitica var nicotianae, were investigated. The bioassay results indicated that compounds 3ad, 3gd, and 3hd showed broad-spectrum antifungal activity in vitro. Compound 3cd exhibited excellent fungicidal activity against Rhizoctonia solani Kuhn, with an EC50 value of 10.9 μg/mL, which was comparable to that of commercial fungicidal triadimefon (EC50 = 6.1 μg/mL). Furthermore, molecular docking study suggested that 3cd had high binding affinities with 1W9U, like argifin.
A new synthetic route of Epalrestat was proposed in this study. The new route abandons the raw material carbon disulfide, which is highly harmful to the environment, and optimizes the key steps in the typical synthesis strategy. Epalrestat was prepared through a three-step process, and the reaction products were characterized. The optimum conditions for the synthesis of the substituted rhodanine intermediate are as follows: under the catalysis of 2.0 equivalents of 25%KOH, ethanol was used as the solvent, and the reaction was carried out at 40 °C for 1 h. The optimal conditions for the synthesis of Epalrestat are as follows: under the catalysis of 2.0 equivalents of 50%KOH, ethanol was used as the solvent, and the reaction was carried out at 40 °C for 5 h.