Benzcatechinborane → (S)-ethyl 2-(2-chloro-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)-2-hydroxyacetate

Participants

Reaction Steps

To a solution of ethyl 2-(2-chloro-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)-2-oxoacetate (0.6621 g, 1.53 mmol), and (R)-2-methyl-CBS-oxazaborolidine (0.098 g, 0.35 mmol) in toluene (6 mL) was added a solution of distilled catecholborane (0.254 g, 2.39 mmol) in toluene (1 mL) over 15 minutes, then stirred for another 45 minutes. The reaction was quenched with saturated sodium carbonate solution and stirred at room temperature for 15 minutes. Product extracted with EtOAc and organic layer washed with saturated sodium carbonate (3×), brine, dried (MgSO4), filtered, concentrated and purified by CombiFlash (0 to 25% EtOAc/Hex) to give product contaminated with (S)-ethyl 2-(2-bromo-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)-2-hydroxyacetate. LCMS-ESI+: calc'd for C13H12ClF3NO6S2: 434.0 (M+H+); Found: 433.9 (M+H+).

Provenance & Evidence