Synthesis of bis-and tetrakis-(ω-dimethylamino)-substituted cross-conjugated polyene α-diketones of the thiophene series

Bis-and tetrakis(ω-dimethylamino)-substituted cross-conjugated polyene α-diketones, containing two thiophene rings, were synthesized from α-diketones of the thiophene series and β-dimethylaminoacrolein aminals and also 2-aza-3-dimethylaminoacrolein acetal.