Lithium Hexamethyldisilazide → 5-Bromo-N-(2,4-dimethoxybenzyl)-2-oxo-N-(1,2,4-thiadiazol-5-yl)-2,3-dihydrobenzo[d]oxazole-6-sulfonamide

Participants

Reaction Steps

Added LHMDS (1603 μl, 1.603 mmol, 1M in THF) to 1-3 (422 mg, 1.679 mmol) in THF (1908 μl) at −78° C. Removed cooling bath and stirred at RT for 30 min. Cooled back to −78 C and slowly added the 35-2 (159 mg, 0.509 mmol) in THF (636 μl). The resulting reaction mixture was allowed to slowly warm to RT while remaining in bath. After 2 h, quenched with 5 mL saturated NH4Cl and diluted with 10 mL EtOAc. Separated layers, back-extracted aqueous with 3×5 mL EtOAc. Dried over Na2SO4, filtered, concentrated to give a clear, orange oil. Purified by normal-phase HPLC (40 g ISCO column, 0-50% EtOAc:Hex) to give 35-3 as a white solid.

Provenance & Evidence