5-Amino-2-methylphenol → 5-Hydrazino-2-methyl-phenol hydrochloride salt

To an ice cold slurry of 4-amino-2-hydroxytoluene (6.22 g, 50.0 mmol), ice (10.0 g) and hydrochloric acid (37% aqueous, 15.0 mL) was added an ice-cold solution of sodium nitrite (3.49 g, 50.0 mmol) in water (10.0 mL) over 30 min. The resultant slurry was added over 30 min to an ice-cold slurry of tin (II) chloride (25.3 g, 133 mmol) in water (30.0 mL) and hydrochloric acid (37% aqueous, 30.0 mL) and the reaction stirred overnight. The mixture was cooled in an ice/water bath and the solid collected by filtration, washing with ice-cold cyclohexane. The residue was dried in vacuo at 50° C. to give the title compound (water retained, 11.1 g). 1H NMR (300 MHz, d4-MeOD): 2.12 (3H, s), 6.38 (1H, dd, J=2.3, 8.0 Hz), 6.44 (1H, d, J=2.3 Hz), 7.02 (1H, d, J=8.1 Hz).

1. temperatureThe mixture was cooled in an ice/water bath
2. filtrationthe solid collected by filtration
3. washwashing with ice-cold cyclohexane
4. customThe residue was dried in vacuo at 50° C.

ORD record

ord-d7dc88ac9347472191ed93b7249b1547

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09440974B2