4-Toluenesulfonyl chloride → Tert-butyl 6-amino-3-bromo-2-(4-methylbenzenesulfonyloxy)benzoate

Participants

Reaction Steps

4-Methylbenzenesulfonyl chloride (2.26 g) was added to a solution of tert-butyl 6-amino-3-bromo-2-hydroxybenzoate (Intermediate 51, 2.85 g), DMAP (1.21 g), and triethylamine (1.5 g) in DCM (40 mL) and left at room temperature for 1 hour. The resulting solution was washed with water, filtered through a phase separator and the filtrate was concentrated in vacuo. The residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-15% to give tert-butyl 6-amino-3-bromo-2-(4-methylbenzenesulfonyloxyl)benzoate (3.51 g) as an off-white solid.

Provenance & Evidence