Phosphorus oxychloride → 2,5-Dichloro-1,1,1,6,6,6-hexafluoro-3,4-diazahexa-2,4-diene

A mixture of N,N-diethylaniline hydrochloride (18.5 g, 0.1 mol), 1,2-bis(trifluoroacetyl)hydrazine (10.3 g, 0.46 mol) and phosphoryl chloride (160 mL) was stirred for 30 minutes under nitrogen in a flask fitted with a condenser leading to a cold trap (−78° C.). The mixture was heated under reflux for 5 h and then allowed to cool and stored overnight. The flask contents and the small amount of material which had condensed in the cold trap were combined and the two layers which had formed were separated. The layer was added to ice water (85 mL) and the mixture vigorously stirred for 1 h in a flask fitted with a condenser. Separation of the lower organic layer gave the main batch of the crude product (6.4 g). The original dark upper layer was treated similarly with ice water (75 mL) and the organic layer subjected to preliminary purification by trap-to-trap distillation in vacuum to afford a second batch of crude product (1.6 g). Distillation of the combined product through a vacuum-jacketed Vigreux column gave 2,5-dichloro-1,1,1,6,6,6-hexafluoro-3,4-diazahexa-2,4-diene (6.3 g, 53%) as an oil.

1. customfitted with a condenser
2. customleading to a cold trap
3. custom(−78° C.)
4. temperatureThe mixture was heated
5. temperatureunder reflux for 5 h
6. temperatureto cool
7. waitstored overnight
8. customcondensed in the cold trap
9. customthe two layers which had formed
10. customwere separated
11. additionThe layer was added to ice water (85 mL)
12. stirringthe mixture vigorously stirred for 1 h in a flask
13. customfitted with a condenser
14. customSeparation of the lower organic layer
15. customgave the main batch of the crude product (6.4 g)
16. customthe organic layer subjected to preliminary purification by trap-to-trap
17. distillationdistillation in vacuum
18. customto afford a second batch of crude product (1.6 g)
19. distillationDistillation of the combined product through a vacuum-jacketed Vigreux column

ORD-Eintrag

ord-c889eed52bd1489b94c9a590baa4b2b3

Quelldatensatz

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08715395B2