4-Bromophenylhydrazine hydrochloride → 1-(p-bromophenyl)-3,5-diphenylpyrazole

In a 500-ml four-necked flask were placed 25.2 g (0.11 mole) of 1,3-diphenylpropanedione, 25.3 g (0.11 mole) of p-bromophenylhydrazine hydrochloride, and 234.7 g of toluene. The mixture was stirred at room temperature and 6.0 g (0.11 mole) of sodium methoxide was added in drops at room temperature. After the addition, the mixture was heated under reflux with stirring for three hours. Upon completion of the reaction, the reaction mixture was cooled to room temperature and a solid was recovered by filtration. The filtrate was concentrated under reduced pressure to dryness. To the residue was added 350 ml of methanol and the mixture was heated with stirring for one hour. Thereafter, the mixture was cooled to room temperature and a solid was recovered by filtration. The solid was washed with methanol and dried under reduced pressure to give 28.4 g of 1-(p-bromophenyl)-3,5-diphenylpyrazole.

1. customIn a 500-ml four-necked flask were placed
2. additionAfter the addition
3. temperaturethe mixture was heated
4. temperatureunder reflux
5. stirringwith stirring for three hours
6. customUpon completion of the reaction
7. temperaturethe reaction mixture was cooled to room temperature
8. filtrationa solid was recovered by filtration
9. concentrationThe filtrate was concentrated under reduced pressure to dryness
10. additionTo the residue was added 350 ml of methanol
11. temperaturethe mixture was heated
12. stirringwith stirring for one hour
13. temperatureThereafter, the mixture was cooled to room temperature
14. filtrationa solid was recovered by filtration
15. washThe solid was washed with methanol
16. customdried under reduced pressure

ORD-Eintrag

ord-0d23d9d2ba29467f81878ea3554623ed

Quelldatensatz

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07816020B2