Chemistry of benzo[b] furan IV.. Chemical behaviour of furo[3,4‐b] ‐benzofuran and synthesis of 4‐Arylbenzofuro[2,3‐d] pyridazines

Furo[3,2‐b]benzofuran was demonstrated to be an intermediate for the synthesis of dibenzofuran and 1,4‐epoxy‐1,4‐dihydrodibenzofuran ring systems. Starting from the readily available aryl 3‐bromomethyl‐2‐benzo[b]furyl ketones, a method was developed for the synthesis of 4‐arylbenzofuro[2,3‐d]pyridazines.