Nitrogen → (R)-tert-Butyl 3-(2-(1-(6-(N-(2,4-dimethoxybenzyl)-N-(1,2,4-thiadiazol-5-yl)sulfamoyl)-5-fluoro-2-oxobenzo[d]oxazol-3(2H)-yl)ethyl)phenyl)-3-fluoroazetidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

In an oven-dried 2 dram vial under N2, added (R)-tert-butyl 3-(2-(1-(6-(N-(2,4-dimethoxybenzyl)-N-(1,2,4-thiadiazol-5-yl)sulfamoyl)-5-fluoro-2-oxobenzo[d]oxazol-3(2H)-yl)ethyl)phenyl)-3-hydroxyazetidine-1-carboxylate (32-3, 55.8 mg, 0.075 mmol) to DCM (376 μl) and cooled to −78° C. Added DAST (19.88 μl, 0.150 mmol) dropwise. After 30 min at −78° C., removed from bath and allowed to slowly warm to RT. After 20 min, LCMS showed complete consumption of SM to desired product. Cooled reaction to 0° C., slowly quenched with 3 mL H2O. Diluted with 5 mL DCM, separated layers, back-extracted aqueous with 1×5 mL DCM. Washed combined organics with 1×5 mL H2O, 1×5 mL brine. Dried combined organics over Na2SO4, filtered, concentrated to give 32-5 as a white solid. Carried crude material forward to subsequent step.

Provenance & Evidence