Trifluoroacetic acid → Trifluoroacetic acid

Participants

Reaction Conditions

Reaction Steps

TFA (0.40 mL) was added to a 0° C. solution of sodium (2S,5R)-2-(5-(tert-butoxycarbonylaminomethyl)isoxazol-3-yl)-7-oxo-1,6-diaza-bicyclo[3.2.1]octan-6-yl sulfate (54 mg, 0.12 mmol) in dry DCM (1.2 mL). The reaction mixture was stirred at 0° C. for 30 minutes to 1 h and then diluted with diethyl ether. The precipitate was collected via centrifugation, washed with ether (3×) and further dried under high vacuum to provide (2S,5R)-2-(5-(aminomethyl)isoxazol-3-yl)-7-oxo-1,6-diazabicyclo[3.2.1]octan-6-yl hydrogen sulfate as a TFA salt (˜30 mg). ESI-MS (EI+, m/z): 319.2. The TFA salt (˜30 mg) was further purified by prep-HPLC using ammonium formate buffer to provide (2S,5R)-2-(5-(aminomethyl)isoxazol-3-yl)-7-oxo-1,6-diazabicyclo[3.2.1]octan-6-yl hydrogen sulfate (601, 10 mg, 26%) as a white solid. ESI-MS (EI+, m/z): 319.21. 1H NMR (300 MHz, D2O) δ 6.61 (s, 1H), 4.68-4.65 (m, 1H), 4.35 (s, 2H), 4.17-4.14 (m, 1H), 3.14-3.10 (m, 1H), 2.95-2.91 (m, 1H), 2.31-1.80 (m, 4H).

Provenance & Evidence