If free from OH bands in the IR, then recrystallise it from Et2O or pet ether; otherwise treat it with SOCl2 at 50o for 30minutes, evaporate, dry the residue over KOH in a vacuum and recrystallise it. The (±)-acid chloride has m 85o [Bartlett & Knox Org Synth 45 14 1965]. Itis characterised as the amide (prisms from EtOH) m 132o, [ ] 17 (+) and (-) 1.5o (EtOH). On repeated recrystallisation from EtOH the anilide has m 120.5-121o, [] 25 +76o (c 1, CHCl3). [Read & Storey J Chem Soc 2761 1930, Sutherland & Shriner J Am Chem Soc 58 62 1936, Halterman et al. J Am Chem Soc 109 8105 1987, Bartlet & Knox Org Synth 45 55 1945, Beilstein 11 IV 650.]
