| Abstract: | 3-Acetyltropolone ( 1 ) reacted with 2-hydroxybenzaldehyde ( 3a ) in the presence of perchloric acid in ethyl orthoformate to afford 2-(3-tropolonyl)-1-benzopyrylium perchlorate ( 4a ). The reactions with 2-hydroxy-5-methylbenzaldehyde ( 3b ), 5-chloro-2-hydroxybenzaldehyde ( 3c ), and 2-hydroxy-1-naphthalde-hyde ( 3d ) gave respectively the corresponding products 4b-d . The reactions of 2-acetyl-7-methylamino-tropone ( 2 ) with 3a-d also gave the corresponding products 5a-d , respectively. |
