Synthesis of sulfur‐bridged piperazinediones by reaction of 3,6‐dibromo‐1,4‐dimethyl‐2,5‐piperazinedione with geminal dithiols

Abstract

AbstractThe reaction of several geminal dithiols with 3,6‐dibromo‐1,4‐dimethyl‐2,5‐piperazinedione gave in good yields piperazinedione derivatives substituted at the 3,6‐position with a geminal dithiol‐bridging group. These sulfur‐bridged piperazinediones formally represent derivatives of the 2,4‐dithia‐6,8‐diaza‐7,9‐dioxobicyclo[3.2.2]nonane ring system. Attempts to transform these sulfur‐bridged piperazinediones to 3,6‐epidithiopiperazinediones by removal of the bridging group common to the sulfur functionality were unsuccessful. Studies also are reported of addition of thioacetic acid to 3,6‐dimethylene‐2,5‐piperazinedione to give 3,6‐diacetylthio‐3,6‐dimethyl‐2,5‐piperazinedione. Conversion of the 3,6‐diacetylthio derivative to the epithiopiperazinedione ring system yielded a mixture of epimono‐ and epidithiopiperazinediones.