Tiopronin → 3-[1-(Carboxymethylcarbamoyl)ethylsulfanyl]-2-hydroxyacrylic acid ethyl ester

Beteiligte Stoffe

Reaktionsschritte

A solution of N-(2-mercaptopropionyl)glycine (1.17 g, 7.17 mmol) and ethyl bromopyruvate (1 mL, 7.17 mmol, 90% purity) in acetonitrile (30 mL) was stirred at room temperature for 3 h. After removal of the solvent, the residue was dissolved in a mixed solvent of ethanol (15 mL) and water (15 mL). After the pH was adjusted to 7-8 with satd. NaHCO3 solution, the mixture was stirred at room temperature overnight. The mixture was acidified to pH 1-2 with concentrated hydrochloric acid and then rotary evaporated to dryness. The residue was purified by column chromatography eluted with EtOAc giving 3-[1-(carboxymethylcarbamoyl)ethylsulfanyl]-2-hydroxyacrylic acid ethyl ester as yellow solid (1.06 g, yield 53.3%). 1H NMR (CDCl3, 300.16 MHz) δ (ppm): 9.10 (broad s, 1H), 7.22 (d, J=0.9 Hz, 1H), 4.62 (d, J=17.7 Hz, 1H), 4.53 (d, J=17.7 Hz, 1H), 4.28 (q, J=7.1 Hz, 1H), 3.47 (qd, J=6.2 & 0.9 Hz, 1H), 1.48 (d, J=6.2 Hz, 3H) and 1.30 (t, J=7.1 Hz, 3H). 13C NMR (CDCl3, 75.48 MHz) δ (ppm): 174.02, 165.84, 160.57, 130.27, 120.20, 62.04, 46.76, 37.11, 14.45 and 14.09. MS (ESI) m/z: 260 (M+—OH, 100).

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