1-(Triphenylphosphoranylidene)acetone → 4-(3-Oxobutenyl)-benzonitrile

HRID 2225443Notes

Reaction equation

HRID 2225443 reaction equation
[C:1]([C:3]1[CH:10]=[CH:9][C:6]([CH:7]=O)=[CH:5][CH:4]=1)#[N:2].[CH:11](=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[C:12]([CH3:14])=[O:13]>ClCCl>[O:13]=[C:12]([CH3:14])[CH:11]=[CH:7][C:6]1[CH:9]=[CH:10][C:3]([C:1]#[N:2])=[CH:4][CH:5]=1

Participants

4

Reactant 2

HCID 150381-(Triphenylphosphoranylidene)acetoneHCID 660424-Cyanobenzaldehyde

Product 1

HCID 538903834-(3-Oxobutenyl)-benzonitrileYield 80%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

By stirring 3.02 g of 4-cyanobenzaldehyde and 7.32 g of acetonylidene-triphenylphosphorane in 50 ml of dichloromethane and then recrystallizing from isopropanol, 3.15 g (80%) of 4-(3-oxobutenyl)-benzonitrile is obtained. 1.71 g of it is mixed in 20 ml of dichloromethane with 20 ml of a 0.5 M solution of bromine in dichloromethane. After decolorization, the solvent is drawn off in a vacuum. The remaining oil is refluxed with 0.95 g of imidazole and 7 ml of triethylamine in 40 ml of toluene for 2 hours. A precipitate is filtered off, the filtrate is distributed in ethyl acetate-2M hydrochloric acid, the hydrochloric acid phase is alkalized with potassium carbonate and extracted with ethyl acetate. 1.2 g of a crude product is obtained, which, after recrystallization from isopropanol, yields the Z-isomer with mp. 131°-135° C. After chromatography of the mother liquor on silica gel (eluant ethyl acetate), the E-isomer is obtained from ethyl acetate/ether as crystals of mp: 123°-126° C.

Workup

  1. customrecrystallizing from isopropanol

Sources & evidence

ORD record
ord-a0c8123ca4534dd5815ab46510ad91f3
Source dataset
uspto-grants-1994_09
Patent number
US05344834

Reaction notes

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