(Triphenylphosphoranylidene)acetonitrile → HCID 23050238, Verbindung
Reaktionsgleichung
[CH3:1][O:2][C:3]1[C:13]([O:14][CH3:15])=[CH:12][C:6]2[S:7][C:8]([CH:10]=O)=[CH:9][C:5]=2[CH:4]=1.[C:16]([CH:18]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)#[N:17]>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]1[C:13]([O:14][CH3:15])=[CH:12][C:6]2[S:7][C:8](/[CH:10]=[CH:18]/[C:16]#[N:17])=[CH:9][C:5]=2[CH:4]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A mixture of 5,6-dimethoxybenzo[b]thiophene-2-carboxaldehyde (8.14 g) and cyanomethylene triphenylphosphorane (22.06 g) in dry toluene (270 ml) was stirred and heated to reflux for 1 hour. The reaction mixture was then evaporated to dryness and the residue was dissolved in a mixture of dichloromethane (50 ml) and toluene (50 ml) and passed through a column of coarse silica (0.2-0.5 mm, Merck, 600 g). The column was eluted with toluene:ethyl acetate (4:1 v/v). The appropriate fractions were combined and evaporated to dryness and the residue was crystallised from dichloromethane:diethyl ether to give pure (E)-3-(5,6-dimethoxy-benzo[b]thiophene-2-yl)-2-propenenitrile (7.56 g), m.p. 154°-158° C.