Reactions of 3‐acetyl‐2‐aminotropones and 2‐acetyl‐7‐aminotropones with hydrazine

Abstract 3‐Acetyl‐2‐aminotropone (1a) reacted with hydrazine to afford its hydrazone (3a) and 3‐methyl‐1,8‐dihydrocycloheptapyrazol‐8‐one (4), while methylamino‐ and pyrrolidinyl‐substituted compounds 1b and 1c gave only the cyclized compound (4). Reactions of 2‐acetyl‐7‐aminotropones 2a‐d gave their hydrazones 5a‐d and the hydrazone 6. The hydrazones 3a and 5b were heated in acetic acid to give 4 and 3‐methyl‐8‐methylamino‐1,2‐diazaazulene (7), respectively. Several reactions of 4 and 6 were also described.