KF/Al2O3/PEG-400: An Efficient Catalytic System for the Fiesselmann-Type Synthesis of Thiophene Derivatives

A simple and mild protocol has been developed for the synthesis of novel steroidal and nonsteroidal thiophene derivatives from beta-halo-alpha,beta-unsaturated aldehydes using KF/Al2O3/PEG-400 as an efficient catalytic system. The beta-halo-alpha,beta-unsaturated aldehydes are synthesized from the corresponding ketones using Vilsmeier formylation reaction and converted into beta-halo-alpha, beta-unsaturated nitriles. The synthetic protocol is subsequently applied to the synthesis of 3-aminothiophene derivatives using beta-halo-alpha, beta-unsaturated nitriles.