Hydrochloric Acid → 3-Chloro-4-fluorophenylhydrazine hydrochloride

In a 500 ml round bottom flask provided with efficient stirring and external cooling arrangement, 51 ml (, 0.5 mole) of conc. HCl was cooled to below 5 deg C and 25 gms (0.13 mole) 3-chloro-4-fluoroaniline was added. The hydrochloride thus precipitated was then diazotised below 0 deg C with 12 gms (0.17 mole)sodium nitrite and the resulting diazonium salt was decomposed with 100 gms (0.79 mole)sodium sulphite and 12 ml caustic lye. The reaction mixture was filtered to remove impurities.225 ml conc. HCl was added and stirred well and allowed to stand overnight. The 3-chloro-4-fluorophenylhydrazine hydrochloride thus precipitated was filtered and recrystallized from water. The dried product was 18 gms (yield 69%) M.pt: decomposed at 193 deg C. IR (KBr) cm−1 2939 and 2690(NH), 1506 (C═C), 1114 (C—F), 744(C—Cl)

1. customIn a 500 ml round bottom flask provided
2. customThe hydrochloride thus precipitated
3. customdiazotised below 0 deg C
4. filtrationThe reaction mixture was filtered
5. customto remove impurities
6. addition225 ml conc. HCl was added
7. stirringstirred well
8. customThe 3-chloro-4-fluorophenylhydrazine hydrochloride thus precipitated
9. filtrationwas filtered
10. customrecrystallized from water
11. customdecomposed at 193 deg C

ORD record

ord-5c8a61bade6e41afaef01c22d254b8aa

Source dataset

uspto-grants-2002_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06403629B2