Hydrochloric Acid → (4-Bromo-2-methylphenyl)hydrazine hydrochloride

To a solution of 4-bromo-2-methylaniline (2.50 g, 13.44 mmol) in concentrated HCl (5.4 mL) at 0° C. was added a cold solution of sodium nitrite (1.02 g, 14.78 mmol) in water (5.1 mL). Stirring was continued at 0° C. for 45 min then the mixture was filtered. To the filtrate at 0° C. was added a solution of tin(II) chloride in concentrated HCl (9.5 mL). The reaction mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was made basic at 0° C. with 40% NaOH solution and extracted three times with diethyl ether. The combined organic extracts was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulting solid was treated with 1.25 M HCl in methanol (30 mL), stirred for 10 min at 0° C. then concentrated in vacuo to give a pale yellow solid. The solid was triturated with diethyl ether and dried in vacuo to give (4-bromo-2-methylphenyl)hydrazine hydrochloride (2.26 g, 71%) as an off-white solid: 1H NMR (DMSO-d6, 300 MHz): δ 10.27 (br s, 3H), 7.97 (br s, 1H), 7.35 (m, 2H), 6.89 (d, J=8.2 Hz, 1H), 2.18 (s, 3H).

1. filtrationthe mixture was filtered
2. additionTo the filtrate at 0° C. was added a solution of tin(II) chloride in concentrated HCl (9.5 mL)
3. stirringstirred overnight
4. customwas made basic at 0° C. with 40% NaOH solution
5. extractionextracted three times with diethyl ether
6. washThe combined organic extracts was washed with brine
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. additionThe resulting solid was treated with 1.25 M HCl in methanol (30 mL)
11. stirringstirred for 10 min at 0° C.
12. concentrationthen concentrated in vacuo
13. customto give a pale yellow solid
14. customThe solid was triturated with diethyl ether
15. customdried in vacuo

ORD record

ord-628a4da5d1924aacb6a56ff2f7d89aee

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08575186B2