Diethyl Ether → (5-Bromo-2-methylphenyl)hydrazine--hydrogen chloride (1/1)

Temperature

0 °C

To a suspension of 5-bromo-2-methylaniline (4.80 g, 25.8 mmol) in concentrated HCl (16 mL) was added dropwise a solution of sodium nitrite (1.96 g, 28.4 mmol) in water (10 mL) over 30 minutes at 0° C. To the mixture was added dropwise a solution of SnCl2.2H2O (17.46 g, 77.4 mmol) in concentrated HCl (15 mL) over 50 minutes. After stirring for 1 hour at 0° C., the reaction mixture was basified with 50% NaOH (30 mL). The mixture was further diluted with water (20 mL) and treated with another 50% NaOH (10 mL) and then crushed ice (100 g). The reaction mixture was extracted with ether (3×100 mL) and the combined organic phases were washed with brine, dried over Na2SO4, and filtered. The filtrate was acidified by adding an anhydrous solution of HCl in ether (1 N in ether, 31 mL, 31 mmol). The precipitate was collected and dried under reduced pressure to give 4.57 g (75%) of title compound as a white amorphous solid. 1H NMR (DMSO): 300 MHz δ 10.31 (bs, 3H), 8.11 (bs, 1H), 7.12 (s, 1H), 7.06 (m, 2H), 2.14 (s, 3H).

1. extractionThe reaction mixture was extracted with ether (3×100 mL)
2. washthe combined organic phases were washed with brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. customThe precipitate was collected
6. customdried under reduced pressure

ORD record

ord-59f55b2fa7c745e5b43e8799cefe0ed7

Source dataset

uspto-grants-2005_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06964979B2