1,4‐pentandien‐3‐ones, XXXII: Reaction of 2‐acetylthiophene and 2‐acetylfuran with malononitrile and aldehydes, and synthesis and properties of phenylene‐bis [(thienyl/furyl)nicotinonitrile] derivative

The ( E )‐1‐hetaryl‐2‐propen‐1‐ones 3 and 4 are prepared by condensation of 2‐acetylthiophenes (1a,1c,1d) or 2‐acetylfuran (1b) with aldehydes. The Michael adducts 5/6 are obtained from 3/4 by reaction with malononitrile/LDA in THF at −78°C, or in DMSO with NaH at room temp. Reaction of 3/4 with malononitrile and methylate in methanol yielded the substituted nicotinonitriles 7/8. From terephthalaldehyde, the diketones 9 are prepared, which yield with malononitrile the phenylene‐bis[(thienyl/furyl)nicotinonitrile] derivatives 10 under similiar conditions. Structural and spectral data are discussed.