反应详情

To a stirred mixture of 4-bromo-2-nitroaniline (694 mg, 3.2 mmol) in TFA (5 mL) at −15° C. under argon was added NaBH(OAc)3 (1.1 g, 5.3 mmol) portionwise. The mixture was stirred for 10 min. To the stirred mixture was added dropwise 2-(methylthio)benzo[d]thiazole-6-carbaldehyde (735 mg, 3.5 mmol) from Step 1 of this Example in CH2Cl2 (3 mL). The mixture was stirred for 1 h and then 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-N-((2-(methylthio)benzo[d]thiazol-6-yl)methyl)-2-nitroaniline (1.0 g, 77%) as a yellow solid. 1H NMR (300 MHz, DMSO-d6) δ 8.84 (t, J=6.0 Hz, 1H), 8.19 (d, J=2.4 Hz, 1H), 7.98 (s, 1H), 7.81 (d, J=8.3 Hz, 1H), 7.56 (dd, J=2.4, 9.3 Hz, 1H), 7.46 (d, J=8.3 Hz, 1H), 6.88 (d, J=9.2 Hz, 1H), 4.75 (d, J=6.0 Hz, 2H), 2.77 (s, 3H). LCMS (ESI) m/z 410 and 412 (M+H)+.

1. stirringThe mixture was stirred for 1 h
2. concentrationconcentrated under reduced pressure
3. customThe residue was purified by silica gel flash chromatography
4. washeluting with a gradient of 100% hexanes to 100% EtOAc