Potassium Iodide → 3-Chloro-6-[4-(2-fluorophenyl)piperazin-1-yl]pyridazine

HRID 359422Notes

Reaction equation

[Cl:1][C:2]1[N:3]=[N:4][C:5](Cl)=[CH:6][CH:7]=1.[F:9][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=1[N:16]1[CH2:21][CH2:20][NH:19][CH2:18][CH2:17]1.C(=O)([O-])[O-].[Na+].[Na+].[I-].[K+]>O.CN(C)C=O>[Cl:1][C:2]1[N:3]=[N:4][C:5]([N:19]2[CH2:18][CH2:17][N:16]([C:11]3[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=3[F:9])[CH2:21][CH2:20]2)=[CH:6][CH:7]=1

Participants

Conditions

Temperature: 60 °C

Procedure

A mixture of 3.1 parts of 3,6-dichloropyridazine, 3 parts of 1-(2-fluorophenyl)piperazine, 3.2 parts of sodium carbonate, 0.1 parts of potassium iodide and 72 parts of N,N-dimethylformamide was stirred and heated over weekend at 60° C. The reaction mixture was poured into water. The precipitated product was filtered off and dissolved in trichloromethane. The organic layer was dried, filtered and evaporated. The residue was purified by filtration over silica gel using a mixture of trichloromethane and methanol (98:2 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of 2-propanol and 2,2'-oxybispropane, yielding 4.5 parts (77%) of 3-chloro-6-[4-(2-fluorophenyl)-1-piperazinyl]pyridazine; mp. 148.0° C. (compound 9).

Workup

filtrationThe precipitated product was filtered off
dissolutiondissolved in trichloromethane
customThe organic layer was dried
filtrationfiltered
customevaporated
filtrationThe residue was purified by filtration over silica gel using
additiona mixture of trichloromethane and methanol (98:2 by volume) as eluent
customThe pure fractions were collected
customthe eluent was evaporated
customThe residue was crystallized from a mixture of 2-propanol and 2,2'-oxybispropane

Sources & evidence

ORD record: ord-c4fa555cb5584d4f85beb41ffa95bb89
Source dataset: uspto-grants-1991_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05001125

Reaction notes

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