Thiamphenicol is a semi-synthetic chloramphenicol prepared by total synthesis from thiophenol in which the nitro moiety of chloramphenicol is replaced by a methylsulphone, first synthesised at Sterling Winthrop in 1952. Thiamphenicol is a broad spectrum antibiotic with good activity against Gram negative and anaerobic bacteria. Thiamphenicol acts by binding to the 23S sub-unit of the 50S ribosome inhibiting protein synthesis. Thiamphenicol has been extensively studied with over 800 literature citations.