Hydrochloric Acid → (2R)-3-[3-bromo-4-(1,1-dioxido-3-oxoisothiazolidin-5-yl)phenyl]-2-[(phenylsulfonyl)-amino]propanoic Acid

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Reaction Steps

Methyl (2S)-2-amino-3-[3-bromo-4-(1,1-dioxido-3-oxoisothiazolidin-5-yl)-phenyl]-propanoate trifluoroacetate (77.1 mg, 0.152 mmol) in methanol (1.7 mL,) was treated with triethylamine (85.0 μL, 0.610 mmol) and then benzenesulfonyl chloride (29.2 μL, 0.228 mmol). The solution was stirred at rt for 2 h. 4 M lithium hydroxide in water (0.38 mL) was added and stirred for 3 h at rt. The solution was acidified with aqueous 1 N hydrochloric acid solution (4 mL), diluted with methanol (1.5 mL) and purified by preparative LCMS to afford product as a white solid (55.4 mg, 70%). 1H NMR (400 MHz, CD3OD): δ 7.65–7.62 (m, 2H), 7.53–7.36 (m, 4H), 7.25–7.20 (m, 1H), 5.65 (t, J=6.8 Hz, 1H), 4.06–5.01 (m, 1H), 3.48 (dd, J=16.2, 8.0 Hz, 1H), 3.38–3.28 (m, 1H), 3.11–3.06 (m, 1H), 2.87–2.83 (m, 1H); LCMS found for C18H18BrN2O7S2 (M+H)+: m/z=517.

Provenance & Evidence