Phosphorus oxychloride → 2-Chloro-4-[1-sec-butyl-3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine

HRID 2359039Notes

Reaction equation

[CH:1]([N:5]1[CH:9]=[C:8]([C:10]2[CH:15]=[CH:14][N+:13]([O-])=[CH:12][CH:11]=2)[C:7]([C:17]2[S:18][C:19]([Cl:22])=[CH:20][CH:21]=2)=[N:6]1)([CH2:3][CH3:4])[CH3:2].P(Cl)(Cl)([Cl:25])=O>>[Cl:25][C:14]1[CH:15]=[C:10]([C:8]2[C:7]([C:17]3[S:18][C:19]([Cl:22])=[CH:20][CH:21]=3)=[N:6][N:5]([CH:1]([CH2:3][CH3:4])[CH3:2])[CH:9]=2)[CH:11]=[CH:12][N:13]=1

Participants

Reactant 2

HCID 24813Phosphorus oxychloride

HCID 67260857HCID 67260857, compound

Product 1

HCID 866579212-Chloro-4-[1-sec-butyl-3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridineYield 29%

Procedure

4-[1-sec-butyl-3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine-N-oxide (6.1 mmol) was stirred in 20 mL of phosphorous oxychloride at 120° C. for 5 h. The solvent was then evaporated and the residue was treated with methanol and evaporated again. The residue was purified by chromatography on silica gel (hepthane:ethyl acetate 5:1 to 3:1) to afford 623 mg of 2-Chloro-4-[1-sec-butyl-3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine (29% yield).

Workup

customThe solvent was then evaporated
additionthe residue was treated with methanol
customevaporated again
customThe residue was purified by chromatography on silica gel (hepthane:ethyl acetate 5:1 to 3:1)

Sources & evidence

ORD record: ord-49639819b4444ada8fb587a53961be1e
Source dataset: uspto-grants-2014_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08685974B2

Reaction notes

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