Reactions of 3-acetyltropolone methyl ethers with guanidine and amidines

Abstract

3-Acetyl-2-methoxytropone (1a) rearranged to 2-acetylbenzoic acid (2) on treatment with guanidine in the presence of sodium ethoxide, and reacted with benzamidine to give 4-methyl-2-phenyl-9H-cyclohepta[d]pyrimidin-9-one (5). Reaction with guanidine carbonate in the absence of sodium ethoxide gave 2-amino-4-methyl-9H-cyclohepta[d]pyrimidin-9-one (4). 2-Acetyl-7-methoxytropone (1 b) reacted with guanidine, benzamidine, and acetamidine to afford 4-acetyl-2-aminocycloheptimidazole (3), 4-acetyl-2-phenylcycloheptimidazole (6), and 2-acetyl-7-aminotropone (7), respectively.