THIENO[3,2-B]BENZOFURAN - SYNTHESIS AND REACTIONS

Thieno[3,2-b]benzofuran was synthesized starting from benzo[b]furan-3( 2H)-one or benzo[b]furan-2-carbaldehyde. Electrophilic substitution re actions such as bromination, formylation, acetylation or nitration, ta ke place in position 2. An electron donating group in position 2 direc ts further electrophilic substitution into positions 3 and 6, whereas compounds with an electron acceptor in position 2 are substituted excl usively in position 6. Metallation with butyllithium took place in pos ition 2. The H-1 and C-13 NMR signals of the title compound were fully assigned.