Streamlined synthesis of 3-azabicyclo [2.2.2] oct-3-one hydrochloride: enhanced and simplified approach

The quinuclidine ring system, found in various natural products and pivotal in synthesizing therapeutic compounds such as azasetron and palonosetron, holds significant importance. Azabicyclo[2.2.2]oct-3-one derivatives, derivatives of this ring system, exhibit diverse biological activities ranging from anti-cancer to antihistaminic properties. Moreover, they serve as key components in catalysts for asymmetric reactions. However, the conventional synthesis method for azabicyclo[2.2.2]oct-3-one hydrochloride suffers from drawbacks like the use of toxic pyridine rings and expensive catalysts, making large-scale production unfeasible. In response, we propose a novel synthesis route utilizing isonepecotic acid, offering simplicity, safety, and cost-effectiveness while avoiding harsh conditions and the need for expensive catalysts. This approach presents a scalable and economically viable alternative for the synthesis of 3-azabicyclo[2.2.2]oct-3-one hydrochloride.