Hydrochloric Acid → 2-(3,4-Dichlorophenyl)pent-4-enenitrile

HRID 844558Notes

Reaction equation

[Cl:1][C:2]1[CH:3]=[C:4]([CH2:9][C:10]#[N:11])[CH:5]=[CH:6][C:7]=1[Cl:8].[CH:12]([N-]C(C)C)([CH3:14])[CH3:13].[Li+].C(Br)C=C.Cl>O1CCCC1.C1CCCCC1>[C:10]([CH:9]([C:4]1[CH:5]=[CH:6][C:7]([Cl:8])=[C:2]([Cl:1])[CH:3]=1)[CH2:14][CH:12]=[CH2:13])#[N:11]

Participants

Conditions

Temperature: -70 °C

Procedure

3,4-Dichlorophenylacetonitrile (80 g) was dissolved in anhydrous tetrahydrofuran (800 ml) under a nitrogen atmosphere, cooled to −70° C., and lithium di-isopropylamide (320 ml of a 1.5M solution in cyclohexane) added. The mixture was stirred at −70° C. for 30 minutes, allyl bromide (63 g) added over 15 minutes and the mixture stirred for a further 30 minutes. 2N Aqueous hydrochloric acid solution (600 ml) was then added and the mixture extracted twice with diethyl ether. The organic extracts were combined and the solvent removed under reduced pressure. The resulting residue was dissolved in dichloromethane, dried over anhydrous sodium sulphate and the solvent removed under reduced pressure to give a red mobile oil. This was chromatographed on silica gel eluting with 4:1, by volume, hexane:dichloromethane to give 4-cyano-4-(3,4-dichlorophenyl)but-1-ene (94.8 g) as an oil.

Workup

stirringthe mixture stirred for a further 30 minutes
extractionthe mixture extracted twice with diethyl ether
customthe solvent removed under reduced pressure
dissolutionThe resulting residue was dissolved in dichloromethane
dry with materialdried over anhydrous sodium sulphate
customthe solvent removed under reduced pressure
customto give a red mobile oil
customThis was chromatographed on silica gel eluting with 4:1, by volume, hexane

Sources & evidence

ORD record: ord-a62a6a95c43648f2b8c9a45c27e6dbfb
Source dataset: uspto-grants-2002_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06380396B1

Reaction notes

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