Reaction Steps
To a solution of 1-(((Z)-(2-(((2R,3S)-2-((4-(aminomethyl)-1H-1,2,3-triazol-1-yl)methyl)-4-oxo-1-sulfoazetidin-3-yl)amino)-1-(2-aminothiazol-4-yl)-2oxoethylidene)amino)oxy)cyclopropane-carboxylic acid (559 mg, 1.06 mmol) and Pyrazole-1-carboxamidine hydrochloride (310 mg, 2.12 mmol) in DMF (12 mL) was added DIPEA (1.48 mL, 8.45 mmol). After 16 h of stirring at rt, the solution was diluted with toluene (20 mL), causing a dense oil to separate out. The top layer was decanted and the remaining oil was purified by reverse phase prep HPLC (XSelect CSH, 30×100 mm, 5 μm, C18 column; ACN-water with 0.1% formic acid modifier, 60 mL/min), affording the title compound (240 mg, 39%) as a white powder. LCMS: Rt=0.28 min, m/z=572.0 (M+H) Method 2m_acidic; 1H NMR (400 MHz, D2O) δ 8.09 (s, 1H), 7.18 (s, 1H), 5.52 (d, J=5.4 Hz, 1H), 4.97 (dd, J=14.1, 5.5 Hz, 1H), 4.91 (q, J=5.5 Hz, 1H), 4.84-4.76 (m, 1H assumed; partially obscured by solvent residual peak), 4.55 (s, 2H), 1.49-1.36 (m, 2H), 1.34-1.23 (m, 2H). E-isomer was also obtained. LCMS: Rt=0.32 min, m/z=572.0 (M+H) Method 2m_acidic. 1H NMR (400 MHz, DMSO-d6) δ 9.37 (d, J=9.6 Hz, 1H), 8.11 (s, 1H), 7.41 (s, 1H), 7.13 (s, 2H), 6.50 (s, 1H), 5.18 (dd, J=9.6, 5.3 Hz, 1H), 4.97 (d, J=13.5 Hz, 1H), 4.76-4.58 (m, 1H), 4.52 (dd, J=16.11, 7.70 Hz, 1H), 4.26-4.05 (m, 2H), 1.86-2.08 (m, 1H), 1.34-1.07 (m, 6H).
