Ethyl ester of thiosalicylic acid combining a soft nucleophilic –SH with an ethyl ester handle. Compared with the methyl analogue it shows slightly higher lipophilicity (log P 2.8) and boiling point, making it preferred for high-temperature reactions and fragrance applications. Key uses include:
Pharmaceutical & biotech intermediate: reacts with farnesyl bromide to give ethyl farnesyl thiosalicylate, which is hydrolysed to the anti-cancer Ras-inhibitor farnesyl thiosalicylic acid (FTS) ;
Agro-chemical building block: Cu-coupling affords ethyl (aryl-thio)benzoates used as rice-blast fungicides;
High-temperature RAFT chain-transfer agent for acrylic and methacrylic resins; the ethyl ester reduces volatility and odour during 120–150 °C processing;
Savoury flavour & fragrance: GRAS status (FEMA 4768); 0.5–2 ppm provides roasted coffee/onion notes with lower volatility than the methyl ester;
Metal-surface treatment: forms densely packed SAMs on gold, lowering surface energy and enhancing SERS sensitivity for mercury detection.
Store under nitrogen at 2–8 °C, away from light and oxidants; avoid strong bases to prevent thio-ester hydrolysis.
