Hydrochloric Acid → (S)-2-amino-4-(methylthio)butane-1-sulfonic acid hydrochloride

Participants

Reaction Steps

Sodium (S)-2-(tert-butoxycarbonylamino)-4-(methylthio)butane-1-sulfonate (350 mg) was treated with 6 N HCl in water at 40° C. for 1 h. The reaction mixture was purified on Diaion HP-20 column eluting with water (200 mL), then 20% CH3CN in water. The fractions were concentrated and dried under vacuum to give (S)-2-amino-4-(methylthio)butane-1-sulfonic acid hydrochloride as a light yellow solid (53 mg, 21%). 1H NMR (DMSO-d6, 300 MHz) d 8.05 (br s, 3H, NH3), 3.4 (br s, 1H, NCH), 2.65 (m, 4H, SCH2 and OSCH2), 2.1 (s, 3H, SCH3), 1.8-2.1 (m, 2H, NCHCH2CH2SCH3). LC-MS: 0.15 min (eluted along with solvent peak); MS (ESI−) m/z 198 (M−1)+. Purity: >95% by 1H NMR and LC-MS. The chirality of the final product was based on the commercially available starting material, (S)-tert-butyl 1-hydroxy-4-(methylthio)butan-2-ylcarbamate, which has a natural configuration (L−). The reactions did not change the chiral center.

Provenance & Evidence