Trifluoromethanesulfonic anhydride → HCID 86701004, compound

Participants

Reaction Conditions

Reaction Steps

Tf2O (8.0 mL, 0.0474 mol) was added dropwise to a −78° C. solution of tert-butyl 4-(2-((2S,5R)-6-(benzyloxy)-7-oxo-1,6-diaza-bicyclo[3.2.1]octane-2-carbonyl)hydrazinyl)-4-oxobutylcarbamate (7.5 g, 0.0158 mol) and Py (10.2 mL, 0.126 mol) in dry DCM (120 mL). The reaction mixture was allowed to warm to 0° C. then the reaction mixture was stirred at 0° C. for 3 hrs. Sat. NaHCO3 was added at 0° C. very slowly. The organic layer was separated and the water layer was exacted with DCM (3×). The combined organic layer was washed with water, saturated sodium chloride, dried over Na2SO4, and concentrated. The residue was purified by silica gel column (gradient elution 0˜25% EtOAc/petroleum ether) to afford tert-butyl 3-(5-((2S,5R)-6-(benzyloxy)-7-oxo-1,6-diaza-bicyclo[3.2.1]octan-2-yl)-1,3,4-oxadiazol-2-yl)propylcarbamate (3.9 g, 54%) as a yellow solid. ESI-MS (EI+, m/z): 458 [M+H]+. 1H NMR (500 MHz, CDCl3) δ 7.45-7.37 (m, 5H), 5.08 (d, J=14.5 Hz, 1H), 4.93 (d, J=14.5 Hz, 1H), 4.70-4.66 (m, 1H), 3.37 (br s, 1H), 3.23-3.21 (m, 2H), 2.94-2.88 (m, 3H), 2.79 (d, J=14.5 Hz, 1H), 2.30-2.28 (m, 2H), 2.11-1.97 (m, 4H), 1.45 (s, 9H).

Provenance & Evidence