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

HRID 1533041Notes

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-c872e9ea9ec249bd880314cec5e68a56
Source dataset: uspto-grants-2001_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06207678B1

Reaction notes

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