Lawesson's reagent → tert-butyl ((5-((2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octan-2-yl)-1,3,4-thiadiazol-2-yl)methyl)carbamate

Participants

Reaction Conditions

Reaction Steps

Lawesson's reagent (0.68 g, 1.68 mol) was added to a solution of tert-butyl 2-(2-((2S,5R)-6-(benzyloxy)-7-oxo-1,6-diaza-bicyclo[3.2.1]octane-2-carbonyl)hydrazinyl)-2-oxoethylcarbamate (0.50 g, 1.12 mmol) in THF (30 mL). The reaction mixture was heated at 70° C. for 0.5 h. The solution was cooled down to rt and saturated NaHCO3 was added. The organic layer was separated and the aqueous layer was exacted with EtOAc (2×). The combined organic layer was dried over Na2SO4, and concentrated. The crude sample was dissolved in THF (100 mL), and Hg(OAc)2 (1.68 g) was added. The mixture was stirred at rt overnight, filtered and concentrated. The residue was dissolved in EtOAc (100 mL), stirred for 30 min, filtered and concentrated. The crude material was purified by silica gel column chromatography (20% to 50% EtOAc/petroleum ether) to give tert-butyl ((5-((2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octan-2-yl)-1,3,4-thiadiazol-2-yl)methyl)carbamate (230 mg, 45%) as a white solid. ESI-MS (EI+, m/z): 446.2 [M+H]+.

Provenance & Evidence