Purification Methods
Recrystallise 2-(2-thienyl)glycine by dissolving it in H2O (1g in 3 mL), adjusting the pH to 5.5 with aqueous NH3, diluting with MeOH (20 mL), stirring, adjusting the pH to 5.5 and cooling to 0o. Also recrystallise it from small volumes of H2O. [R-isomer: Nishimura et al. Nippon Kagaku Zasshi 82 1688 1961, S-isomer: Johnson & Panetta Chem Abstr 63 14869 1965, Johnson & Hardcastle Chem Abstr 66 10930 1967, RS-isomer: LiBassi et al. Gazz Chim Ital 107 253 1977.] The (±) N-acetyl derivative has m 191o (from H2O) [Schouteenten et al. Bull Soc Chim Fr II 248, II 252 1978].