Hydrochloric Acid → 4-(3,4-Dichlorophenyl)-5-hydroxypent-1-ene

HRID 844560Notes

Reaction equation

[BH4-].[Na+].[Cl:3][C:4]1[CH:5]=[C:6]([CH:11]([CH:15]=[O:16])[CH2:12][CH:13]=[CH2:14])[CH:7]=[CH:8][C:9]=1[Cl:10].Cl>C(O)C.O>[Cl:3][C:4]1[CH:5]=[C:6]([CH:11]([CH2:15][OH:16])[CH2:12][CH:13]=[CH2:14])[CH:7]=[CH:8][C:9]=1[Cl:10]

Participants

Conditions

Temperature: 0 °C

Procedure

Sodium borohydride (2.2 g) was added in four portions, over 10 minutes, to an ice-cooled solution of 4-(3,4-dichlorophenyl)-4-formylbut-1-ene (13 g) (see Preparation 21) in ethanol (100 ml). The mixture was stirred for a further 30 minutes before removing the solvent under reduced pressure to give a residue. This was suspended in water (50 ml), cooled to 0° C. and the mixture acidified (pH<6) with 2N aqueous hydrochloric acid solution. The mixture was extracted three times with dichloromethane, the organic phases combined and the solvent removed under reduced pressure. Dichloromethane (200 ml) was then added, the mixture stirred and filtered and the solvent removed from the filtrate under reduced pressure to give an oil. This was chromatographed on silica gel eluting with dichloromethane to give 4-(3,4-dichlorophenyl)-5-hydroxypent-1-ene (7 g) as a orange oil.

Workup

custombefore removing the solvent under reduced pressure
customto give a residue
extractionThe mixture was extracted three times with dichloromethane
customthe solvent removed under reduced pressure
additionDichloromethane (200 ml) was then added
stirringthe mixture stirred
filtrationfiltered
customthe solvent removed from the filtrate under reduced pressure
customto give an oil
customThis was chromatographed on silica gel eluting with dichloromethane

Sources & evidence

ORD record: ord-d3e5af4c19ec443893d4fe7f37cd8a9d
Source dataset: uspto-grants-2002_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06380396B1

Reaction notes

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