Dimethylformamide → 3-Bromo-4-trifluoromethyl-6-(4-trifluoromethyl-phenyl)-pyridazine

HRID 1293729Notes

Reaction equation

[F:1][C:2]([F:21])([F:20])[C:3]1[C:4](=O)[NH:5][N:6]=[C:7]([C:9]2[CH:14]=[CH:13][C:12]([C:15]([F:18])([F:17])[F:16])=[CH:11][CH:10]=2)[CH:8]=1.P(Br)(Br)([Br:24])=O.CN(C=O)C>>[Br:24][C:4]1[N:5]=[N:6][C:7]([C:9]2[CH:14]=[CH:13][C:12]([C:15]([F:18])([F:17])[F:16])=[CH:11][CH:10]=2)=[CH:8][C:3]=1[C:2]([F:21])([F:20])[F:1]

Participants

Reactant 3

HCID 6228Dimethylformamide

HCID 24613Phosphorus oxybromide

HCID 872319844-Trifluoromethyl-6-(4-trifluoromethyl-phenyl)-2h-pyridazin-3-one

Product 1

HCID 866080213-Bromo-4-trifluoromethyl-6-(4-trifluoromethyl-phenyl)-pyridazineYield 97.5%

Conditions

Temperature: 105 °C

Procedure

A mixture of 4-trifluoromethyl-6-(4-trifluoromethyl-phenyl)-2H-pyridazin-3-one (example C.26 step 6) (9.61 g, 31 mmol), POBr3 (26.8 g, 94 mmol) and DMF (0.72 mL, 9 mmol) was stirred for 3 h at 105° C. under nitrogen atmosphere. The reaction mixture was poured (the mixture was nearly solid) onto water (300 mL) and stirred for 2 h at 23° C., the precipitated solid was filtered off and applied onto silica gel for silica gel column chromatography with heptane/EtOAc 4:1->2:1 to give the title compound as a light brown solid (11.22 g, 97%). MS (ISP) 371 [(M+H)+], 373 [(M+2+H)+]; mp 123–125° C.

Workup

additionThe reaction mixture was poured (the mixture
stirringstirred for 2 h at 23° C.
filtrationthe precipitated solid was filtered off

Sources & evidence

ORD record: ord-a9d7a04b120b44e58dd7a8cf27b8093b
Source dataset: uspto-grants-2007_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07238808B2

Reaction notes

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