Abstract
Syntheses of 1-methyl-2-phenyl-1, 2, 3, 4, 5-pentahydro-10H-benzo[5, 6]cyclohepta[1, 2-c]pyrazole-3, 10-dione (3a) and its aminoalkylidene derivatives (3b-d) were investigated. Treatment of 3a with N-bromosuccinimide gave 4 (5)-bromo-1-methyl-2-phenyl-1, 2, 3-trihydro-10H-benzo[5, 6]cyclohepta[1, 2-c]pyrazole-3, 10-dione (13), while reaction of 3a with N-chlorosuccinimide produced 2-phenyl-2, 3, 3a, 4, 5-pentahydro-10H-benzo[5, 6]cyclohepta[1, 2-c]pyrazole-3, 10-dione (15). Dehydrogenation of 3a at 310°with palladium on carbon catalyst afforded 1-methyl-2-phenyl-1, 2, 3-trihydro-10H-benzo[5, 6]cyclohepta[1, 2-c]pyrazole-3, 10-dione (18) in a trace.
