Recrystallise thiamphenicol from H2O or CHCl3. The UV has max at 224, 266 and 274nm ( 13,700, 800 and 700) in 95% EtOH. The 1S,2S-isomer [1478651-7] has m 164.3-166.3o (from H2O/EtOAc/pet ether) and [] D 25 -12.6o (c 1, EtOH); and the racemate 1RS,2RS-Racefenical [847-25-6] has m 181-183o (dec) from CHCl3/EtOAc/pet ether. [Cutler et al. J Am Chem Soc 74 5475, 5482 1952, UV: Nachod & Cutler J Am Chem Soc 74 1291 1952, Suter et al. J Am Chem Soc 75 4330 1953, Cutler et al. J Am Pharm Assoc 43 687 1954, Beilstein 13 IV 2957.]