Sodium Thiosulfate → 4-O-tert-butyl 1-O-[(4-methoxyphenyl)methyl] (2S)-2-[(Z)-[2-[[(5R,6R,7R)-2-benzhydryloxycarbonyl-3-(chloromethyl)-5,8-dioxo-5lambda4-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl]amino]-1-[5-chloro-2-[(2-methylpropan-2-yl)oxycarbonylamino]-1,3-thiazol-4-yl]-2-oxoethylidene]amino]oxybutanedioate

Participants

Reaction Steps

To a solution of (S)-4-tert-butyl 1-(4-methoxybenzyl) 2-(((Z)-(2-(((6R,7R)-2-((benzhydryl oxy)carbonyl)-3-(chloromethyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl)amino)-1-(2-((tert-butoxycarbonyl)amino)-5-chlorothiazol-4-yl)-2-oxoethylidene)amino)oxy)succinate (27.5 g, 27.2 mmol) in Dichloromethane (DCM) (IL) at −40° C. was added dropwise a solution of m-CPBA (6.40 g, 28.6 mmol) in Dichloromethane (DCM) (200 mL) over 10 min. The mixture was stirred at the same temperature over 30 min. LCMS indicated completion of the reaction. The mixture was treated with 15% aq. Na2S2O3 (200 mL). The organic solution was separated and washed with 5% NaHCO3 (400 mL), brine (400 mL), dried (Na2SO4), filtered, and concentrated (temperature of the water bath should not be too high—apx. 25° C.). The residue was purified by CombiFlash automated silica gel chromatography (220 g column), eluting with EtOAc/Hexanes (0-60%) to afford (S)-4-tert-butyl 1-(4-methoxybenzyl) 2-(((Z)-(2-(((5R,6R,7R)-2-((benzhydryloxy)carbonyl)-3-(chloromethyl)-5-oxido-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl)amino)-1-(2-((tert-butoxycarbonyl)amino)-5-chlorothiazol-4-yl)-2-oxoethylidene)amino)oxy)succinate (27.5 g, 25.4 mmol, 94% yield) as a light yellow foaming solid. LCMS: (M+H)+: 1026.3

Provenance & Evidence