Reactions of 3‐isopropyl‐, 3‐isopropenyl‐, and 3‐acetyltropolone methyl ethers with guanidines. Synthesis of 9 H ‐cyclohepta[d]pyrimidin‐9‐ones and cycloheptimidazoles

3‐Isopropyl‐ and 3‐isopropenyltropolone methyl ethers reacted with guanidine, 1‐methylguanidine, and 1,1‐dimethylguanidine to afford the corresponding 4‐isopropyl‐ and 4‐isopropenylcycloheptimidazoles 4a‐f , respectively. The reactions of 3‐acetyl‐2‐methoxytropones 2c‐e with guanidines afforded 4‐methyl‐9 H ‐cyclohepta[ d ]pyrimidin‐9‐ones 8a‐i , while the reactions of 7‐acetyl‐2‐methoxytropones 3c,d produced 4‐acetylcycloheptimidazoles 4g‐1 . From these reactions, several minor products were also isolated.