Studies on 1-Azabicyclo Compounds. XV. Oxidation of 1, 3, 4, 6, 11, 11a-Hexahydro-2H-pyrazino [1, 2-b] isoquinolin-1-one Derivatives with Mercuric Acetate, and Their Conversion into 1, 2, 3, 4, 5, 6, 7, 8-Octahydro-2-methyl-2, 5-benzodiazecine and Related Compounds

Abstract

Oxidation of hexahydro-2H-pyrazino [1, 2-b] isoquinolin-1-one (Ia) with mercuric acetate gave the α-aminocarbinol (II), which was characterized as the quaternary ammonium bromide (III). Mercuric acetate oxidation of the diamine (VII), however, afforded the lactam (VIII). Treatment of the methiodides (XIIa, XIIb, and XIIc) with lithium in liquid ammonia yielded the piperazinones (XIIIa, XIIIb, and XIIIc), respectively. On the other hand, reduction of the methiodides (XIIa, XIIb, and XIIc) with sodium amalgam furnished selectively the ten-membered aminolactams (XVIa, XVIb, and XVIc), respectively, in fair yields, which were converted to the corresponding ten-membered diamines (XVIIa, XVIIb, and XVIIc).