Acetic Acid → 4-bromo-5-methoxy-N1-((2-(methylthio)benzo[d]thiazol-6-yl)methyl)benzene-1,2-diamine

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Reaction Steps

To a stirred suspension of 4-bromo-5-methoxy-N-((2-(methylthio)benzo[d]thiazol-6-yl)methyl)-2-nitroaniline (212 mg, 0.5 mmol) from Step 1 of this Example in EtOH (4 mL) and HOAc (2 mL) at 0° C. under argon was added zinc powder (160 mg, 2.4 mmol) in one portion. After 1.5 h at 0° C., MeOH (5 mL), additional HOAc (2 mL), and zinc powder (160 mg, 2.4 mmol) were added. The mixture was allowed to warm to rt and stirred for 18 h. The mixture was filtered and the filtrate was cooled to 0° C. The pH of the filtrate was adjusted to pH˜9 by addition of solid Na2CO3. The mixture was then partitioned between EtOAc (150 mL) and water (100 mL). The EtOAc layer was separated, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography eluting with a gradient of 100% hexanes to 100% EtOAc to afford 4-bromo-5-methoxy-N1-((2-(methylthio)benzo[d]thiazol-6-yl)methyl)benzene-1,2-diamine (120 mg, 61%). LCMS (ESI) m/z 410 and 412 (M+H)+.

Provenance & Evidence