Facile Synthesis of 5-Substituted 2-Acetylthiophenes

5-Substituted 2-(α-alkoxyimino)ethylthiophenes 4-8 are obtained by the reaction of 2-(α-alkoxyimino)ethylthiophenes 3 and electrophilic reagents. Hydrolysis of thiophenes 4-8 produces 5-substituted 2-acetylthiophenes 9-13, respectively. Compounds 3 are easily obtained either by the reaction of 2-acetylthiophene (1) and an O-alkylhydroxylamine or by oxidation of 1 followed by O-alkylation.