Synthesis of Pyrazolone Derivatives. XXXVII. Synthetic and Pharmacological Studies on the Related Compounds of (4S, 7R)-2-Amino-7, 8, 8-trimethyl-4, 5, 6, 7-tetrahydro-4, 7-methano-2H-indazole

Abstract

Oxidation of (4S, 7R)-2-amino-4, 7-methano-2H-indazole (2) with Pb (OAc)₄ resulted in ring expansion to give (5S, 8R)-5, 8-methano-1, 2, 3-benzotriazine (5). Irradiation of 5 resulted in photolytic loss of nitrogen to give (1R, 3S)-ethynylcyclopentanecarbonitrile (6) by a radical reaction. Compound 2 was converted to (4S, 7R)-2-substituted-4, 7-methano-2H-indazoles (8, 10, 12, 13, 14 and 15) and pyridazino [1, 6-b] indazoles (9 and 11). Compound 5 showed prominent central nervous system stimulant activity in mice.