A simple and mild protocol has been developed for the synthesis of novel steroidal and nonsteroidal thiophene derivatives from β-halo-α,β-unsaturated aldehydes using KF/Al2O3/PEG-400 as an efficient catalytic system. The β-halo-α,β-unsaturated aldehydes are synthesized from the corresponding ketones using Vilsmeier formylation reaction and converted into β-halo-α,β-unsaturated nitriles. The synthetic protocol is subsequently applied to the synthesis of 3-aminothiophene derivatives using β-halo-α,β-unsaturated nitriles.
Key words
Fiesselmann synthesis - KF/Al
2O
3/PEG-400 - thiophene - unsaturated aldehyde - unsaturated nitrile
