3-Chloroaniline → (3-Chlorophenyl)hydrazine

3-chloroaniline (K-IV) (1 eq., 50 g) was dissolved at −5 to 0° C. in concentrated HCl (300 ml) and stirred for 10 min. A mixture of NaNO2 (1.2 eq., 32.4 g), water (30 ml), SnCl2.2H2O (2.2 eq., 70.6 g) and concentrated HCl (100 ml) was added dropwise over a period of 3 h while maintaining the temperature. After stirring for a further 2 h at −5 to 0° C., the reaction mixture was set to pH 9 using NaOH solution and extracted with EtOAc (250 ml). The combined organic phases were dried over magnesium sulfate and the solvent was removed under vacuum. The purification by column chromatography (SiO2, 8% EtOAc/hexane) produced 40 g (72% yield) of (3-chlorophenyl)hydrazine (K-IV) as a brown oil.

1. additionwas added dropwise over a period of 3 h
2. temperaturewhile maintaining the temperature
3. stirringAfter stirring for a further 2 h at −5 to 0° C.
4. extractionextracted with EtOAc (250 ml)
5. dry with materialThe combined organic phases were dried over magnesium sulfate
6. customthe solvent was removed under vacuum
7. customThe purification by column chromatography (SiO2, 8% EtOAc/hexane)

ORD record

ord-60bbe18a14604dc2a1a4a71c4eae42c0

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08946204B2