Citric Acid → 2-(3,4-Dichlorophenyl)pent-4-enal

HRID 844559Notes

Reaction equation

[C:1]([CH:3]([C:7]1[CH:12]=[CH:11][C:10]([Cl:13])=[C:9]([Cl:14])[CH:8]=1)[CH2:4][CH:5]=[CH2:6])#N.[H-].C([Al+]CC(C)C)C(C)C.O.C(O)(=O)CC(CC(O)=O)(C(O)=O)[OH:29]>C1(C)C=CC=CC=1>[Cl:14][C:9]1[CH:8]=[C:7]([CH:3]([CH:1]=[O:29])[CH2:4][CH:5]=[CH2:6])[CH:12]=[CH:11][C:10]=1[Cl:13]

Participants

Conditions

Temperature: -70 °C

Procedure

4-Cyano-4-(3,4-dichlorophenyl)but-1-ene (13 g) (see Preparation 20) was dissolved in anhydrous toluene (100 ml) and cooled to −70° C. under a nitrogen atmosphere. Diisobutylaluminium hydride (50 ml of a 1.5M solution in toluene) was added to the solution over 30 minutes, the mixture stirred at −70° C. for a further 30 minutes and then allowed to warm slowly to −10° C. Water (6 ml) was carefully added (exothermic reaction) before pouring the mixture into a 15% (by weight) aqueous solution of citric acid (500 ml), followed by further addition of toluene (300 ml) and vigorous stirring of the mixture for 30 minutes. The two phases were separated, the organic phase washed with brine, dried over anhydrous sodium sulphate and the solvent removed under reduced pressure to give 4-(3,4-dichlorophenyl)-4-formylbut-1-ene as an oil (14 g).

Workup

temperatureto warm slowly to −10° C
custom(exothermic reaction)
stirringvigorous stirring of the mixture for 30 minutes
customThe two phases were separated
washthe organic phase washed with brine
dry with materialdried over anhydrous sodium sulphate
customthe solvent removed under reduced pressure

Sources & evidence

ORD record: ord-3db923cd1fb14d3c9d6c0e41de6504f9
Source dataset: uspto-grants-2002_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06380396B1

Reaction notes

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