4-Cyanobenzaldehyde → 1,3-bis(4-cyanophenyl)prop-2-en-1-one

Participants

Reaction Steps

The synthesis employed for the 2,4-substituted dicationic furans 1-6 used 2,4-bis(4-cyanophenyl)furan as the key intermediate and is outlined in scheme 1. This key compound was obtained through a four step approach. A base catalyzed Aldol condensation between 4-cyanobenzaldehyde and 4-acetylbenzonitrile in methanol gave 1,3-bis(4-cyanophenyl)prop-2-en-1-one. Bromination of the double bond of the chalcone (i) in CHCl3 yielded 1,3-bis(4-cyanophenyl)-2,3-dibromopropan-1-one (ii), which was reacted with 2.5 equivalent of MeONa in MeOH to form 1,3-bis(4-cyanophenyl)-3-methoxyprop-2-en-1-one (iii) (Weygand, C.; Bauer, E.; Hennig, H., Ueber Beziehungen zwischen Polymorphismus und Ethylen-Stereomerie. B. 1929, 62, 562-573). The reaction of dimethylsulfonium methylide with the enolether (iii) gave 2,4-disubstituted furan (iv) (Harris, C. M. et al., J. Org. Chem. 1974, 39, 72-77).

Provenance & Evidence