4-Bromo-5-methoxy-2-nitroaniline → 4-Bromo-5-methoxybenzene-1,2-diamine

Temperature

0 °C

To a stirred mixture of 4-bromo-5-methoxy-2-nitroaniline (5 g, 20 mmol) in MeOH (50 mL) and HOAc (20 mL) at 0° C. under argon was added zinc powder (5.3 g, 80 mmol) portionwise. The mixture was stirred for 2 h, then 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 (250 mL) and water (200 mL). The EtOAc layer was separated, dried over Na2SO4, filtered, and concentrated under reduced pressure to afford 4-bromo-5-methoxybenzene-1,2-diamine (3.8 g, 88%) as a dark purple solid. The material was used in the next step without further purification. 1H NMR (300 MHz, DMSO-d6) δ 6.66 (s, 1H), 6.34 (s, 1H), 4.08-4.83 (m, 4H), 3.63 (s, 3H). LCMS (ESI) m/z 217 and 219 (M+H)+.

1. filtrationfiltered
2. additionThe pH of the filtrate was adjusted to pH˜9 by addition of solid Na2CO3
3. customThe mixture was then partitioned between EtOAc (250 mL) and water (200 mL)
4. customThe EtOAc layer was separated
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure

ORD record

ord-f2f34895402f4e58a5634a43243c7f30

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08952058B2